1645263144 has 128 divisors (see below), whose sum is σ = 5311872000. Its totient is φ = 462082752.

The previous prime is 1645263133. The next prime is 1645263161. The reversal of 1645263144 is 4413625461.

1645263144 is a `hidden beast` number, since 1 + 6 + 452 + 63 + 144 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1645263099 and 1645263108.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 79987 + ... + 98429.

It is an arithmetic number, because the mean of its divisors is an integer number (41499000).

Almost surely, 2^1645263144 is an apocalyptic number.

1645263144 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1645263144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2655936000).

1645263144 is an abundant number, since it is smaller than the sum of its proper divisors (3666608856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1645263144 is a wasteful number, since it uses less digits than its factorization.

1645263144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18524 (or 18514 counting only the distinct ones).

The product of its digits is 69120, while the sum is 36.

The square root of 1645263144 is about 40561.8434492319. The cubic root of 1645263144 is about 1180.5338827059.

The spelling of 1645263144 in words is "one billion, six hundred forty-five million, two hundred sixty-three thousand, one hundred forty-four".