31520479 has 2 divisors, whose sum is σ = 31520480. Its totient is φ = 31520478.

The previous prime is 31520453. The next prime is 31520483. The reversal of 31520479 is 97402513.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31520479 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31520479.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31520179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15760239 + 15760240.

It is an arithmetic number, because the mean of its divisors is an integer number (15760240).

Almost surely, 2^31520479 is an apocalyptic number.

31520479 is a deficient number, since it is larger than the sum of its proper divisors (1).

31520479 is an equidigital number, since it uses as much as digits as its factorization.

31520479 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 31520479 is about 5614.3101980564. The cubic root of 31520479 is about 315.8864056534.

The spelling of 31520479 in words is "thirty-one million, five hundred twenty thousand, four hundred seventy-nine".