645265020 has 24 divisors (see below), whose sum is σ = 1806742224. Its totient is φ = 172070656.

The previous prime is 645264989. The next prime is 645265057. The reversal of 645265020 is 20562546.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5377149 + ... + 5377268.

It is an arithmetic number, because the mean of its divisors is an integer number (75280926).

Almost surely, 2^645265020 is an apocalyptic number.

645265020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645265020 is an abundant number, since it is smaller than the sum of its proper divisors (1161477204).

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

645265020 is a wasteful number, since it uses less digits than its factorization.

645265020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10754429 (or 10754427 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 645265020 is about 25402.0672387111. The cubic root of 645265020 is about 864.1305797581.

The spelling of 645265020 in words is "six hundred forty-five million, two hundred sixty-five thousand, twenty".