645936963 has 24 divisors (see below), whose sum is σ = 1002875328. Its totient is φ = 368733456.

The previous prime is 645936961. The next prime is 645936983. The reversal of 645936963 is 369639546.

It is a happy number.

It is not a de Polignac number, because 645936963 - 2¹ = 645936961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645936961) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 216520 + ... + 219482.

It is an arithmetic number, because the mean of its divisors is an integer number (41786472).

Almost surely, 2^645936963 is an apocalyptic number.

645936963 is a deficient number, since it is larger than the sum of its proper divisors (356938365).

645936963 is a wasteful number, since it uses less digits than its factorization.

645936963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4463 (or 4456 counting only the distinct ones).

The product of its digits is 3149280, while the sum is 51.

The square root of 645936963 is about 25415.2899452279. The cubic root of 645936963 is about 864.4304281624.

The spelling of 645936963 in words is "six hundred forty-five million, nine hundred thirty-six thousand, nine hundred sixty-three".