31388380 has 24 divisors (see below), whose sum is σ = 69385680. Its totient is φ = 11894400.

The previous prime is 31388377. The next prime is 31388381. The reversal of 31388380 is 8388313.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31388381) 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 7 ways as a sum of consecutive naturals, for example, 40921 + ... + 41680.

It is an arithmetic number, because the mean of its divisors is an integer number (2891070).

Almost surely, 2^31388380 is an apocalyptic number.

It is an amenable number.

31388380 is an abundant number, since it is smaller than the sum of its proper divisors (37997300).

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

31388380 is a wasteful number, since it uses less digits than its factorization.

31388380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82629 (or 82627 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 31388380 is about 5602.5333555455. The cubic root of 31388380 is about 315.4445055653. Note that the first 3 decimals are identical.

The spelling of 31388380 in words is "thirty-one million, three hundred eighty-eight thousand, three hundred eighty".