645246321631 has 8 divisors (see below), whose sum is σ = 682783617024. Its totient is φ = 608499285240.

The previous prime is 645246321617. The next prime is 645246321653. The reversal of 645246321631 is 136123642546.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 645246321631 - 2⁹ = 645246321119 is a prime.

It is a super-3 number, since 3×645246321631³ (a number of 36 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645246321691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 197563071 + ... + 197566336.

It is an arithmetic number, because the mean of its divisors is an integer number (85347952128).

Almost surely, 2^645246321631 is an apocalyptic number.

645246321631 is a deficient number, since it is larger than the sum of its proper divisors (37537295393).

645246321631 is a wasteful number, since it uses less digits than its factorization.

645246321631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395129501.

The product of its digits is 622080, while the sum is 43.

The spelling of 645246321631 in words is "six hundred forty-five billion, two hundred forty-six million, three hundred twenty-one thousand, six hundred thirty-one".