31220620 has 24 divisors (see below), whose sum is σ = 65669184. Its totient is φ = 12468096.

The previous prime is 31220603. The next prime is 31220621. The reversal of 31220620 is 2602213.

It is a super-2 number, since 2×31220620² = 1949454226368800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31220594 and 31220603.

It is not an unprimeable number, because it can be changed into a prime (31220621) 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 7 ways as a sum of consecutive naturals, for example, 21229 + ... + 22651.

It is an arithmetic number, because the mean of its divisors is an integer number (2736216).

Almost surely, 2^31220620 is an apocalyptic number.

It is an amenable number.

31220620 is an abundant number, since it is smaller than the sum of its proper divisors (34448564).

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

31220620 is a wasteful number, since it uses less digits than its factorization.

31220620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2529 (or 2527 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 31220620 is about 5587.5414987273. The cubic root of 31220620 is about 314.8815209084.

Adding to 31220620 its reverse (2602213), we get a palindrome (33822833).

The spelling of 31220620 in words is "thirty-one million, two hundred twenty thousand, six hundred twenty".