31328388 has 144 divisors (see below), whose sum is σ = 99555456. Its totient is φ = 8087040.

The previous prime is 31328347. The next prime is 31328389. The reversal of 31328388 is 88382313.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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 (31328389) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 239083 + ... + 239213.

Almost surely, 2^31328388 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 31328388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49777728).

31328388 is an abundant number, since it is smaller than the sum of its proper divisors (68227068).

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

31328388 is a wasteful number, since it uses less digits than its factorization.

31328388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234 (or 229 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 31328388 is about 5597.1767883461. The cubic root of 31328388 is about 315.2434097453.

The spelling of 31328388 in words is "thirty-one million, three hundred twenty-eight thousand, three hundred eighty-eight".