13612820 has 48 divisors (see below), whose sum is σ = 31561488. Its totient is φ = 4899840.

The previous prime is 13612799. The next prime is 13612831. The reversal of 13612820 is 2821631.

It can be written as a sum of positive squares in 8 ways, for example, as 2775556 + 10837264 = 1666^2 + 3292^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10022 + ... + 11298.

It is an arithmetic number, because the mean of its divisors is an integer number (657531).

Almost surely, 2^13612820 is an apocalyptic number.

13612820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13612820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15780744).

13612820 is an abundant number, since it is smaller than the sum of its proper divisors (17948668).

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

13612820 is a wasteful number, since it uses less digits than its factorization.

13612820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1340 (or 1338 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 13612820 is about 3689.5555287866. Note that the first 4 decimals coincide. The cubic root of 13612820 is about 238.7716170590.

The spelling of 13612820 in words is "thirteen million, six hundred twelve thousand, eight hundred twenty".