645360021015 has 16 divisors (see below), whose sum is σ = 1034928153600. Its totient is φ = 343407971232.

The previous prime is 645360021013. The next prime is 645360021017. The reversal of 645360021015 is 510120063546.

It is an interprime number because it is at equal distance from previous prime (645360021013) and next prime (645360021017).

It is not a de Polignac number, because 645360021015 - 2¹ = 645360021013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645360021013) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 48995695 + ... + 49008864.

It is an arithmetic number, because the mean of its divisors is an integer number (64683009600).

Almost surely, 2^645360021015 is an apocalyptic number.

645360021015 is a deficient number, since it is larger than the sum of its proper divisors (389568132585).

645360021015 is a wasteful number, since it uses less digits than its factorization.

645360021015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98005006.

The product of its (nonzero) digits is 21600, while the sum is 33.

The spelling of 645360021015 in words is "six hundred forty-five billion, three hundred sixty million, twenty-one thousand, fifteen".