31978490 has 8 divisors (see below), whose sum is σ = 57561300. Its totient is φ = 12791392.

The previous prime is 31978469. The next prime is 31978511. The reversal of 31978490 is 9487913.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (31978469) and next prime (31978511).

It can be written as a sum of positive squares in 2 ways, for example, as 31820881 + 157609 = 5641^2 + 397^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1598915 + ... + 1598934.

Almost surely, 2^31978490 is an apocalyptic number.

31978490 is a deficient number, since it is larger than the sum of its proper divisors (25582810).

31978490 is a wasteful number, since it uses less digits than its factorization.

31978490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3197856.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 31978490 is about 5654.9526965307. The cubic root of 31978490 is about 317.4090590393.

The spelling of 31978490 in words is "thirty-one million, nine hundred seventy-eight thousand, four hundred ninety".