31240019 has 2 divisors, whose sum is σ = 31240020. Its totient is φ = 31240018.

The previous prime is 31239977. The next prime is 31240021. The reversal of 31240019 is 91004213.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31240019 - 2⁸ = 31239763 is a prime.

It is a super-2 number, since 2×31240019² = 1951877574240722, which contains 22 as substring.

Together with 31240021, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31240519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15620009 + 15620010.

It is an arithmetic number, because the mean of its divisors is an integer number (15620010).

Almost surely, 2^31240019 is an apocalyptic number.

31240019 is a deficient number, since it is larger than the sum of its proper divisors (1).

31240019 is an equidigital number, since it uses as much as digits as its factorization.

31240019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 31240019 is about 5589.2771446762. The cubic root of 31240019 is about 314.9467248443.

The spelling of 31240019 in words is "thirty-one million, two hundred forty thousand, nineteen".