31056667981 has 6 divisors (see below), whose sum is σ = 31230635982. Its totient is φ = 30882726360.

The previous prime is 31056667933. The next prime is 31056668033. The reversal of 31056667981 is 18976665013.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17158380100 + 13898287881 = 130990^2 + 117891^2 .

It is not a de Polignac number, because 31056667981 - 2⁹ = 31056667469 is a prime.

It is a super-2 number, since 2×31056667981² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31056617981) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2364370 + ... + 2377468.

It is an arithmetic number, because the mean of its divisors is an integer number (5205105997).

Almost surely, 2^31056667981 is an apocalyptic number.

It is an amenable number.

31056667981 is a deficient number, since it is larger than the sum of its proper divisors (173968001).

31056667981 is an frugal number, since it uses more digits than its factorization.

31056667981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26379 (or 13280 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 52.

The spelling of 31056667981 in words is "thirty-one billion, fifty-six million, six hundred sixty-seven thousand, nine hundred eighty-one".