31489919 has 2 divisors, whose sum is σ = 31489920. Its totient is φ = 31489918.

The previous prime is 31489901. The next prime is 31489943. The reversal of 31489919 is 91998413.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31489919 - 2⁸ = 31489663 is a prime.

It is a super-2 number, since 2×31489919² = 1983229997253122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31489919.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31489949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15744959 + 15744960.

It is an arithmetic number, because the mean of its divisors is an integer number (15744960).

Almost surely, 2^31489919 is an apocalyptic number.

31489919 is a deficient number, since it is larger than the sum of its proper divisors (1).

31489919 is an equidigital number, since it uses as much as digits as its factorization.

31489919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 44.

The square root of 31489919 is about 5611.5879214354. The cubic root of 31489919 is about 315.7842856950.

The spelling of 31489919 in words is "thirty-one million, four hundred eighty-nine thousand, nine hundred nineteen".