31900019 has 2 divisors, whose sum is σ = 31900020. Its totient is φ = 31900018.

The previous prime is 31899997. The next prime is 31900067. The reversal of 31900019 is 91000913.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31900019 is a prime.

It is a super-2 number, since 2×31900019² = 2035222424400722, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 31899967 and 31900003.

It is not a weakly prime, because it can be changed into another prime (31906019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15950009 + 15950010.

It is an arithmetic number, because the mean of its divisors is an integer number (15950010).

Almost surely, 2^31900019 is an apocalyptic number.

31900019 is a deficient number, since it is larger than the sum of its proper divisors (1).

31900019 is an equidigital number, since it uses as much as digits as its factorization.

31900019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 243, while the sum is 23.

The square root of 31900019 is about 5648.0101805857. The cubic root of 31900019 is about 317.1492197196.

The spelling of 31900019 in words is "thirty-one million, nine hundred thousand, nineteen".