31978423 has 4 divisors (see below), whose sum is σ = 32122048. Its totient is φ = 31834800.

The previous prime is 31978421. The next prime is 31978447. The reversal of 31978423 is 32487913.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31978423 - 2¹ = 31978421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31978421) by changing a digit.

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, 71478 + ... + 71923.

It is an arithmetic number, because the mean of its divisors is an integer number (8030512).

Almost surely, 2^31978423 is an apocalyptic number.

31978423 is a deficient number, since it is larger than the sum of its proper divisors (143625).

31978423 is a wasteful number, since it uses less digits than its factorization.

31978423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143624.

The product of its digits is 36288, while the sum is 37.

The square root of 31978423 is about 5654.9467725170. The cubic root of 31978423 is about 317.4088373650.

The spelling of 31978423 in words is "thirty-one million, nine hundred seventy-eight thousand, four hundred twenty-three".