31157761 has 2 divisors, whose sum is σ = 31157762. Its totient is φ = 31157760.

The previous prime is 31157741. The next prime is 31157767. The reversal of 31157761 is 16775113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20757136 + 10400625 = 4556^2 + 3225^2 .

It is a cyclic number.

It is not a de Polignac number, because 31157761 - 2⁵ = 31157729 is a prime.

It is not a weakly prime, because it can be changed into another prime (31157767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15578880 + 15578881.

It is an arithmetic number, because the mean of its divisors is an integer number (15578881).

Almost surely, 2^31157761 is an apocalyptic number.

It is an amenable number.

31157761 is a deficient number, since it is larger than the sum of its proper divisors (1).

31157761 is an equidigital number, since it uses as much as digits as its factorization.

31157761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4410, while the sum is 31.

The square root of 31157761 is about 5581.9137399283. The cubic root of 31157761 is about 314.6700534434.

The spelling of 31157761 in words is "thirty-one million, one hundred fifty-seven thousand, seven hundred sixty-one".