31513577477 has 2 divisors, whose sum is σ = 31513577478. Its totient is φ = 31513577476.

The previous prime is 31513577461. The next prime is 31513577483. The reversal of 31513577477 is 77477531513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30181765441 + 1331812036 = 173729^2 + 36494^2 .

It is a cyclic number.

It is not a de Polignac number, because 31513577477 - 2⁴ = 31513577461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31513577177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15756788738 + 15756788739.

It is an arithmetic number, because the mean of its divisors is an integer number (15756788739).

Almost surely, 2^31513577477 is an apocalyptic number.

It is an amenable number.

31513577477 is a deficient number, since it is larger than the sum of its proper divisors (1).

31513577477 is an equidigital number, since it uses as much as digits as its factorization.

31513577477 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160900, while the sum is 50.

The spelling of 31513577477 in words is "thirty-one billion, five hundred thirteen million, five hundred seventy-seven thousand, four hundred seventy-seven".