31861332 has 72 divisors (see below), whose sum is σ = 86486400. Its totient is φ = 9854208.

The previous prime is 31861331. The next prime is 31861339. The reversal of 31861332 is 23316813.

It is a happy number.

31861332 is a `hidden beast` number, since 3 + 18 + 613 + 32 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 31861296 and 31861305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31861331) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48019 + ... + 48677.

It is an arithmetic number, because the mean of its divisors is an integer number (1201200).

Almost surely, 2^31861332 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 31861332, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43243200).

31861332 is an abundant number, since it is smaller than the sum of its proper divisors (54625068).

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

31861332 is a wasteful number, since it uses less digits than its factorization.

31861332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765 (or 760 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 31861332 is about 5644.5843071036. The cubic root of 31861332 is about 317.0209594490.

The spelling of 31861332 in words is "thirty-one million, eight hundred sixty-one thousand, three hundred thirty-two".