31656040 has 64 divisors (see below), whose sum is σ = 81239760. Its totient is φ = 10997760.

The previous prime is 31656029. The next prime is 31656049. The reversal of 31656040 is 4065613.

It can be written as a sum of positive squares in 8 ways, for example, as 19166884 + 12489156 = 4378^2 + 3534^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31655996 and 31656014.

It is not an unprimeable number, because it can be changed into a prime (31656049) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7050 + ... + 10630.

Almost surely, 2^31656040 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 31656040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40619880).

31656040 is an abundant number, since it is smaller than the sum of its proper divisors (49583720).

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

31656040 is a wasteful number, since it uses less digits than its factorization.

31656040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3622 (or 3618 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 31656040 is about 5626.3700553732. The cubic root of 31656040 is about 316.3386051571.

The spelling of 31656040 in words is "thirty-one million, six hundred fifty-six thousand, forty".