631643645645 has 8 divisors (see below), whose sum is σ = 758010558456. Its totient is φ = 505289460736.

The previous prime is 631643645599. The next prime is 631643645683. The reversal of 631643645645 is 546546346136.

It can be written as a sum of positive squares in 4 ways, for example, as 23939206729 + 607704438916 = 154723^2 + 779554^2 .

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 631643645645 - 2²⁶ = 631576536781 is a prime.

It is a super-3 number, since 3×631643645645³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3072452 + ... + 3271581.

It is an arithmetic number, because the mean of its divisors is an integer number (94751319807).

Almost surely, 2^631643645645 is an apocalyptic number.

It is an amenable number.

631643645645 is a deficient number, since it is larger than the sum of its proper divisors (126366912811).

631643645645 is a wasteful number, since it uses less digits than its factorization.

631643645645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6363951.

The product of its digits is 18662400, while the sum is 53.

The spelling of 631643645645 in words is "six hundred thirty-one billion, six hundred forty-three million, six hundred forty-five thousand, six hundred forty-five".