1244568645 has 30 divisors (see below), whose sum is σ = 2232277938. Its totient is φ = 663391296.

The previous prime is 1244568641. The next prime is 1244568671. The reversal of 1244568645 is 5468654421.

It is a happy number.

1244568645 is a `hidden beast` number, since 1 + 2 + 44 + 568 + 6 + 45 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 104898564 + 1139670081 = 10242^2 + 33759^2 .

It is not a de Polignac number, because 1244568645 - 2² = 1244568641 is a prime.

It is a super-2 number, since 2×1244568645² = 3097902224234272050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1244568645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1244568641) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 709089 + ... + 710841.

Almost surely, 2^1244568645 is an apocalyptic number.

1244568645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1244568645 is a deficient number, since it is larger than the sum of its proper divisors (987709293).

1244568645 is an frugal number, since it uses more digits than its factorization.

1244568645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3523 (or 1761 counting only the distinct ones).

The product of its digits is 921600, while the sum is 45.

The square root of 1244568645 is about 35278.4444810142. Note that the first 4 decimals coincide. The cubic root of 1244568645 is about 1075.6548798618.

Multiplying 1244568645 by its sum of digits (45), we get a square (56005589025 = 236655²).

1244568645 divided by its sum of digits (45) gives a square (27657081 = 5259²).

The spelling of 1244568645 in words is "one billion, two hundred forty-four million, five hundred sixty-eight thousand, six hundred forty-five".