31387380 has 48 divisors (see below), whose sum is σ = 88724160. Its totient is φ = 8290048.

The previous prime is 31387379. The next prime is 31387393. The reversal of 31387380 is 8378313.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3976 + ... + 8864.

It is an arithmetic number, because the mean of its divisors is an integer number (1848420).

Almost surely, 2^31387380 is an apocalyptic number.

31387380 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31387380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44362080).

31387380 is an abundant number, since it is smaller than the sum of its proper divisors (57336780).

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

31387380 is a wasteful number, since it uses less digits than its factorization.

31387380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5008 (or 5006 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 31387380 is about 5602.4441094936. Note that the first 3 decimals coincide. The cubic root of 31387380 is about 315.4411556223.

The spelling of 31387380 in words is "thirty-one million, three hundred eighty-seven thousand, three hundred eighty".