31142939 has 2 divisors, whose sum is σ = 31142940. Its totient is φ = 31142938.

The previous prime is 31142927. The next prime is 31142953. The reversal of 31142939 is 93924113.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31142939 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (31142039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15571469 + 15571470.

It is an arithmetic number, because the mean of its divisors is an integer number (15571470).

Almost surely, 2^31142939 is an apocalyptic number.

31142939 is a deficient number, since it is larger than the sum of its proper divisors (1).

31142939 is an equidigital number, since it uses as much as digits as its factorization.

31142939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 32.

The square root of 31142939 is about 5580.5859011398. The cubic root of 31142939 is about 314.6201484956.

The spelling of 31142939 in words is "thirty-one million, one hundred forty-two thousand, nine hundred thirty-nine".