1645263244 has 24 divisors (see below), whose sum is σ = 2910252240. Its totient is φ = 813784896.

The previous prime is 1645263241. The next prime is 1645263251. The reversal of 1645263244 is 4423625461.

It is a super-2 number, since 2×1645263244² = 5413782284114807072, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1645263241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 352494 + ... + 357130.

It is an arithmetic number, because the mean of its divisors is an integer number (121260510).

Almost surely, 2^1645263244 is an apocalyptic number.

It is an amenable number.

1645263244 is a deficient number, since it is larger than the sum of its proper divisors (1264988996).

1645263244 is a wasteful number, since it uses less digits than its factorization.

1645263244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5577 (or 5575 counting only the distinct ones).

The product of its digits is 138240, while the sum is 37.

The square root of 1645263244 is about 40561.8446819175. The cubic root of 1645263244 is about 1180.5339066237.

The spelling of 1645263244 in words is "one billion, six hundred forty-five million, two hundred sixty-three thousand, two hundred forty-four".