645620885 has 32 divisors (see below), whose sum is σ = 959949312. Its totient is φ = 405907200.

The previous prime is 645620839. The next prime is 645620897. The reversal of 645620885 is 588026546.

It is not a de Polignac number, because 645620885 - 2¹⁶ = 645555349 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 64007 + ... + 73403.

It is an arithmetic number, because the mean of its divisors is an integer number (29998416).

Almost surely, 2^645620885 is an apocalyptic number.

645620885 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

645620885 is a deficient number, since it is larger than the sum of its proper divisors (314328427).

645620885 is a wasteful number, since it uses less digits than its factorization.

645620885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9573.

The product of its (nonzero) digits is 460800, while the sum is 44.

The square root of 645620885 is about 25409.0709196539. The cubic root of 645620885 is about 864.2894071676.

The spelling of 645620885 in words is "six hundred forty-five million, six hundred twenty thousand, eight hundred eighty-five".