31387392 has 144 divisors (see below), whose sum is σ = 98112000. Its totient is φ = 9870336.

The previous prime is 31387379. The next prime is 31387393. The reversal of 31387392 is 29378313.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31387393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131209 + ... + 131447.

Almost surely, 2^31387392 is an apocalyptic number.

31387392 is a gapful number since it is divisible by the number (32) 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 31387392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49056000).

31387392 is an abundant number, since it is smaller than the sum of its proper divisors (66724608).

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

31387392 is a wasteful number, since it uses less digits than its factorization.

31387392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 263 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 31387392 is about 5602.4451804547. The cubic root of 31387392 is about 315.4411958220.

The spelling of 31387392 in words is "thirty-one million, three hundred eighty-seven thousand, three hundred ninety-two".