631415023721 has 4 divisors (see below), whose sum is σ = 631642399572. Its totient is φ = 631187647872.

The previous prime is 631415023693. The next prime is 631415023777. The reversal of 631415023721 is 127320514136.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 56638764121 + 574776259600 = 237989^2 + 758140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-631415023721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631415023321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113683760 + ... + 113689313.

It is an arithmetic number, because the mean of its divisors is an integer number (157910599893).

Almost surely, 2^631415023721 is an apocalyptic number.

It is an amenable number.

631415023721 is a deficient number, since it is larger than the sum of its proper divisors (227375851).

631415023721 is a wasteful number, since it uses less digits than its factorization.

631415023721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227375850.

The product of its (nonzero) digits is 30240, while the sum is 35.

Adding to 631415023721 its reverse (127320514136), we get a palindrome (758735537857).

The spelling of 631415023721 in words is "six hundred thirty-one billion, four hundred fifteen million, twenty-three thousand, seven hundred twenty-one".