31978449 has 16 divisors (see below), whose sum is σ = 47475840. Its totient is φ = 21273840.

The previous prime is 31978447. The next prime is 31978469. The reversal of 31978449 is 94487913.

It is not a de Polignac number, because 31978449 - 2¹ = 31978447 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31978447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16099 + ... + 17975.

It is an arithmetic number, because the mean of its divisors is an integer number (2967240).

Almost surely, 2^31978449 is an apocalyptic number.

It is an amenable number.

31978449 is a deficient number, since it is larger than the sum of its proper divisors (15497391).

31978449 is a wasteful number, since it uses less digits than its factorization.

31978449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2517 (or 2511 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 31978449 is about 5654.9490713887. The cubic root of 31978449 is about 317.4089233879.

The spelling of 31978449 in words is "thirty-one million, nine hundred seventy-eight thousand, four hundred forty-nine".