31220656 has 20 divisors (see below), whose sum is σ = 60935832. Its totient is φ = 15495296.

The previous prime is 31220641. The next prime is 31220659. The reversal of 31220656 is 65602213.

It is a super-2 number, since 2×31220656² = 1949458722140672, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31220656.

It is not an unprimeable number, because it can be changed into a prime (31220659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4930 + ... + 9313.

Almost surely, 2^31220656 is an apocalyptic number.

It is an amenable number.

31220656 is a deficient number, since it is larger than the sum of its proper divisors (29715176).

31220656 is a wasteful number, since it uses less digits than its factorization.

31220656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14388 (or 14382 counting only the distinct ones).

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

The square root of 31220656 is about 5587.5447201790. The cubic root of 31220656 is about 314.8816419367.

Adding to 31220656 its reverse (65602213), we get a palindrome (96822869).

The spelling of 31220656 in words is "thirty-one million, two hundred twenty thousand, six hundred fifty-six".