645165503331 has 16 divisors (see below), whose sum is σ = 860835962880. Its totient is φ = 429802804640.

The previous prime is 645165503293. The next prime is 645165503351. The reversal of 645165503331 is 133305561546.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 645165503331 - 2⁹ = 645165502819 is a prime.

It is a super-2 number, since 2×645165503331² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (645165503351) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28957726 + ... + 28979996.

It is an arithmetic number, because the mean of its divisors is an integer number (53802247680).

Almost surely, 2^645165503331 is an apocalyptic number.

645165503331 is a deficient number, since it is larger than the sum of its proper divisors (215670459549).

645165503331 is a wasteful number, since it uses less digits than its factorization.

645165503331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28746.

The product of its (nonzero) digits is 486000, while the sum is 42.

The spelling of 645165503331 in words is "six hundred forty-five billion, one hundred sixty-five million, five hundred three thousand, three hundred thirty-one".