31290132 has 48 divisors (see below), whose sum is σ = 77861952. Its totient is φ = 9745920.

The previous prime is 31290089. The next prime is 31290167. The reversal of 31290132 is 23109213.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 31290099 and 31290108.

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, 32782 + ... + 33722.

It is an arithmetic number, because the mean of its divisors is an integer number (1622124).

Almost surely, 2^31290132 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 31290132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38930976).

31290132 is an abundant number, since it is smaller than the sum of its proper divisors (46571820).

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

31290132 is a wasteful number, since it uses less digits than its factorization.

31290132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128 (or 1126 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 31290132 is about 5593.7583072564. The cubic root of 31290132 is about 315.1150398663.

Adding to 31290132 its reverse (23109213), we get a palindrome (54399345).

The spelling of 31290132 in words is "thirty-one million, two hundred ninety thousand, one hundred thirty-two".