31681057 has 2 divisors, whose sum is σ = 31681058. Its totient is φ = 31681056.

The previous prime is 31681043. The next prime is 31681103. The reversal of 31681057 is 75018613.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16966161 + 14714896 = 4119^2 + 3836^2 .

It is an emirp because it is prime and its reverse (75018613) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31681057 - 2¹⁵ = 31648289 is a prime.

It is a Chen prime.

It is equal to p_1955353 and since 31681057 and 1955353 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (31681007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15840528 + 15840529.

It is an arithmetic number, because the mean of its divisors is an integer number (15840529).

Almost surely, 2^31681057 is an apocalyptic number.

It is an amenable number.

31681057 is a deficient number, since it is larger than the sum of its proper divisors (1).

31681057 is an equidigital number, since it uses as much as digits as its factorization.

31681057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 31681057 is about 5628.5928081537. The cubic root of 31681057 is about 316.4219147887.

It can be divided in two parts, 3168 and 1057, that added together give a square (4225 = 65²).

The spelling of 31681057 in words is "thirty-one million, six hundred eighty-one thousand, fifty-seven".