31649879 has 2 divisors, whose sum is σ = 31649880. Its totient is φ = 31649878.

The previous prime is 31649857. The next prime is 31649887. The reversal of 31649879 is 97894613.

It is a strong prime.

It is an emirp because it is prime and its reverse (97894613) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31649879 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31649899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15824939 + 15824940.

It is an arithmetic number, because the mean of its divisors is an integer number (15824940).

Almost surely, 2^31649879 is an apocalyptic number.

31649879 is a deficient number, since it is larger than the sum of its proper divisors (1).

31649879 is an equidigital number, since it uses as much as digits as its factorization.

31649879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 47.

The square root of 31649879 is about 5625.8225176413. The cubic root of 31649879 is about 316.3180815477.

The spelling of 31649879 in words is "thirty-one million, six hundred forty-nine thousand, eight hundred seventy-nine".