31139974477 has 2 divisors, whose sum is σ = 31139974478. Its totient is φ = 31139974476.

The previous prime is 31139974457. The next prime is 31139974483. The reversal of 31139974477 is 77447993113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30343549636 + 796424841 = 174194^2 + 28221^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31139974477 is a prime.

It is a super-2 number, since 2×31139974477² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31139974457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15569987238 + 15569987239.

It is an arithmetic number, because the mean of its divisors is an integer number (15569987239).

Almost surely, 2^31139974477 is an apocalyptic number.

It is an amenable number.

31139974477 is a deficient number, since it is larger than the sum of its proper divisors (1).

31139974477 is an equidigital number, since it uses as much as digits as its factorization.

31139974477 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4000752, while the sum is 55.

The spelling of 31139974477 in words is "thirty-one billion, one hundred thirty-nine million, nine hundred seventy-four thousand, four hundred seventy-seven".