645635830 has 24 divisors (see below), whose sum is σ = 1328602608. Its totient is φ = 221287968.

The previous prime is 645635821. The next prime is 645635831. The reversal of 645635830 is 38536546.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645635831) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 211072 + ... + 214108.

It is an arithmetic number, because the mean of its divisors is an integer number (55358442).

Almost surely, 2^645635830 is an apocalyptic number.

645635830 is an abundant number, since it is smaller than the sum of its proper divisors (682966778).

645635830 is an frugal number, since it uses more digits than its factorization.

645635830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6088 (or 3051 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 40.

The square root of 645635830 is about 25409.3650058399. The cubic root of 645635830 is about 864.2960760480.

The spelling of 645635830 in words is "six hundred forty-five million, six hundred thirty-five thousand, eight hundred thirty".