645121315 has 16 divisors (see below), whose sum is σ = 799983360. Its totient is φ = 498908160.

The previous prime is 645121291. The next prime is 645121331. The reversal of 645121315 is 513121546.

645121315 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 645121315 - 2⁵ = 645121283 is a prime.

It is a super-2 number, since 2×645121315² = 832363022134658450, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 199431 + ... + 202639.

It is an arithmetic number, because the mean of its divisors is an integer number (49998960).

Almost surely, 2^645121315 is an apocalyptic number.

645121315 is a deficient number, since it is larger than the sum of its proper divisors (154862045).

645121315 is a wasteful number, since it uses less digits than its factorization.

645121315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4542.

The product of its digits is 3600, while the sum is 28.

The square root of 645121315 is about 25399.2384728361. The cubic root of 645121315 is about 864.0664257021.

The spelling of 645121315 in words is "six hundred forty-five million, one hundred twenty-one thousand, three hundred fifteen".