31157429 has 2 divisors, whose sum is σ = 31157430. Its totient is φ = 31157428.

The previous prime is 31157419. The next prime is 31157431. The reversal of 31157429 is 92475113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23261329 + 7896100 = 4823^2 + 2810^2 .

It is a cyclic number.

It is not a de Polignac number, because 31157429 - 2²⁴ = 14380213 is a prime.

Together with 31157431, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 31157395 and 31157404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31157419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15578714 + 15578715.

It is an arithmetic number, because the mean of its divisors is an integer number (15578715).

Almost surely, 2^31157429 is an apocalyptic number.

It is an amenable number.

31157429 is a deficient number, since it is larger than the sum of its proper divisors (1).

31157429 is an equidigital number, since it uses as much as digits as its factorization.

31157429 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 32.

The square root of 31157429 is about 5581.8840009445. The cubic root of 31157429 is about 314.6689357889.

The spelling of 31157429 in words is "thirty-one million, one hundred fifty-seven thousand, four hundred twenty-nine".