645626643 has 16 divisors (see below), whose sum is σ = 881632512. Its totient is φ = 420140000.

The previous prime is 645626633. The next prime is 645626647. The reversal of 645626643 is 346626546.

It is a cyclic number.

It is not a de Polignac number, because 645626643 - 2⁴ = 645626627 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645626595 and 645626604.

It is not an unprimeable number, because it can be changed into a prime (645626647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6508 + ... + 36518.

It is an arithmetic number, because the mean of its divisors is an integer number (55102032).

Almost surely, 2^645626643 is an apocalyptic number.

645626643 is a deficient number, since it is larger than the sum of its proper divisors (236005869).

645626643 is a wasteful number, since it uses less digits than its factorization.

645626643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30186.

The product of its digits is 622080, while the sum is 42.

The square root of 645626643 is about 25409.1842253938. The cubic root of 645626643 is about 864.2919765617.

The spelling of 645626643 in words is "six hundred forty-five million, six hundred twenty-six thousand, six hundred forty-three".