645942210 has 32 divisors (see below), whose sum is σ = 1559234880. Its totient is φ = 171254208.

The previous prime is 645942203. The next prime is 645942211. The reversal of 645942210 is 12249546.

It is not an unprimeable number, because it can be changed into a prime (645942211) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 57040 + ... + 67419.

It is an arithmetic number, because the mean of its divisors is an integer number (48726090).

Almost surely, 2^645942210 is an apocalyptic number.

645942210 is an abundant number, since it is smaller than the sum of its proper divisors (913292670).

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

645942210 is a wasteful number, since it uses less digits than its factorization.

645942210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124642.

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 645942210 is about 25415.3931702817. The cubic root of 645942210 is about 864.4327687696.

The spelling of 645942210 in words is "six hundred forty-five million, nine hundred forty-two thousand, two hundred ten".