31986900 has 180 divisors, whose sum is σ = 113430240. Its totient is φ = 7732800.

The previous prime is 31986881. The next prime is 31986917. The reversal of 31986900 is 968913.

It is a tau number, because it is divible by the number of its divisors (180).

It is a super-2 number, since 2×31986900² = 2046323543220000, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 88921 + ... + 89279.

It is an arithmetic number, because the mean of its divisors is an integer number (630168).

Almost surely, 2^31986900 is an apocalyptic number.

31986900 is a gapful number since it is divisible by the number (30) 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 31986900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56715120).

31986900 is an abundant number, since it is smaller than the sum of its proper divisors (81443340).

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

31986900 is a wasteful number, since it uses less digits than its factorization.

31986900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396 (or 380 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 31986900 is about 5655.6962436114. The cubic root of 31986900 is about 317.4368816602.

The spelling of 31986900 in words is "thirty-one million, nine hundred eighty-six thousand, nine hundred".