31668378 has 32 divisors (see below), whose sum is σ = 75534336. Its totient is φ = 8654448.

The previous prime is 31668361. The next prime is 31668379. The reversal of 31668378 is 87386613.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (31668379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15426 + ... + 17357.

It is an arithmetic number, because the mean of its divisors is an integer number (2360448).

Almost surely, 2^31668378 is an apocalyptic number.

31668378 is an abundant number, since it is smaller than the sum of its proper divisors (43865958).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31668378 is a wasteful number, since it uses less digits than its factorization.

31668378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32818.

The product of its digits is 145152, while the sum is 42.

The square root of 31668378 is about 5627.4663926140. The cubic root of 31668378 is about 316.3796976706.

The spelling of 31668378 in words is "thirty-one million, six hundred sixty-eight thousand, three hundred seventy-eight".