31355161 has 2 divisors, whose sum is σ = 31355162. Its totient is φ = 31355160.

The previous prime is 31355143. The next prime is 31355183. The reversal of 31355161 is 16155313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26265625 + 5089536 = 5125^2 + 2256^2 .

It is a cyclic number.

It is not a de Polignac number, because 31355161 - 2¹³ = 31346969 is a prime.

It is a super-2 number, since 2×31355161² = 1966292242671842, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31355131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15677580 + 15677581.

It is an arithmetic number, because the mean of its divisors is an integer number (15677581).

Almost surely, 2^31355161 is an apocalyptic number.

It is an amenable number.

31355161 is a deficient number, since it is larger than the sum of its proper divisors (1).

31355161 is an equidigital number, since it uses as much as digits as its factorization.

31355161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1350, while the sum is 25.

The square root of 31355161 is about 5599.5679297603. The cubic root of 31355161 is about 315.3331857092. Note that the first 3 decimals are identical.

The spelling of 31355161 in words is "thirty-one million, three hundred fifty-five thousand, one hundred sixty-one".