13220631 has 8 divisors (see below), whose sum is σ = 19586160. Its totient is φ = 8813736.

The previous prime is 13220629. The next prime is 13220633. The reversal of 13220631 is 13602231.

13220631 is a `hidden beast` number, since 1 + 32 + 2 + 0 + 631 = 666.

It is an interprime number because it is at equal distance from previous prime (13220629) and next prime (13220633).

It is not a de Polignac number, because 13220631 - 2¹ = 13220629 is a prime.

It is a super-2 number, since 2×13220631² = 349570168076322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13220633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 244800 + ... + 244853.

It is an arithmetic number, because the mean of its divisors is an integer number (2448270).

Almost surely, 2^13220631 is an apocalyptic number.

13220631 is a deficient number, since it is larger than the sum of its proper divisors (6365529).

13220631 is an equidigital number, since it uses as much as digits as its factorization.

13220631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489662 (or 489656 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 13220631 is about 3636.0185643090. The cubic root of 13220631 is about 236.4562119928.

Adding to 13220631 its reverse (13602231), we get a palindrome (26822862).

The spelling of 13220631 in words is "thirteen million, two hundred twenty thousand, six hundred thirty-one".