31423788 has 72 divisors (see below), whose sum is σ = 89893440. Its totient is φ = 9519120.

The previous prime is 31423781. The next prime is 31423789. The reversal of 31423788 is 88732413.

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

It is not an unprimeable number, because it can be changed into a prime (31423781) 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 23 ways as a sum of consecutive naturals, for example, 9223 + ... + 12161.

It is an arithmetic number, because the mean of its divisors is an integer number (1248520).

Almost surely, 2^31423788 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31423788, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44946720).

31423788 is an abundant number, since it is smaller than the sum of its proper divisors (58469652).

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

31423788 is a wasteful number, since it uses less digits than its factorization.

31423788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2969 (or 2955 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 31423788 is about 5605.6924639156. The cubic root of 31423788 is about 315.5630745157.

The spelling of 31423788 in words is "thirty-one million, four hundred twenty-three thousand, seven hundred eighty-eight".