31403029681 has 3 divisors (see below), whose sum is σ = 31403206891. Its totient is φ = 31402852472.

The previous prime is 31403029661. The next prime is 31403029687. The reversal of 31403029681 is 18692030413.

The square root of 31403029681 is 177209.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 19046484081 + 12356545600 = 138009^2 + 111160^2 .

It is not a de Polignac number, because 31403029681 - 2¹⁷ = 31402898609 is a prime.

It is a super-2 number, since 2×31403029681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31403029681.

It is not an unprimeable number, because it can be changed into a prime (31403029687) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 88605 + ... + 265813.

Almost surely, 2^31403029681 is an apocalyptic number.

31403029681 is the 177209-th square number.

31403029681 is the 88605-th centered octagonal number.

It is an amenable number.

31403029681 is a deficient number, since it is larger than the sum of its proper divisors (177210).

31403029681 is an frugal number, since it uses more digits than its factorization.

31403029681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354418 (or 177209 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 37.

The spelling of 31403029681 in words is "thirty-one billion, four hundred three million, twenty-nine thousand, six hundred eighty-one".