13661620 has 24 divisors (see below), whose sum is σ = 32788224. Its totient is φ = 4683936.

The previous prime is 13661603. The next prime is 13661623. The reversal of 13661620 is 2616631.

13661620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×13661620² = 373279722048800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13661623) 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, 48652 + ... + 48931.

It is an arithmetic number, because the mean of its divisors is an integer number (1366176).

Almost surely, 2^13661620 is an apocalyptic number.

13661620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13661620 is an abundant number, since it is smaller than the sum of its proper divisors (19126604).

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

13661620 is a wasteful number, since it uses less digits than its factorization.

13661620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97599 (or 97597 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 13661620 is about 3696.1628751991. The cubic root of 13661620 is about 239.0565974165.

The spelling of 13661620 in words is "thirteen million, six hundred sixty-one thousand, six hundred twenty".