13621780 has 12 divisors (see below), whose sum is σ = 28605780. Its totient is φ = 5448704.

The previous prime is 13621763. The next prime is 13621781. The reversal of 13621780 is 8712631.

It can be written as a sum of positive squares in 2 ways, for example, as 1483524 + 12138256 = 1218^2 + 3484^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13621781) 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, 340525 + ... + 340564.

It is an arithmetic number, because the mean of its divisors is an integer number (2383815).

Almost surely, 2^13621780 is an apocalyptic number.

13621780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13621780 is an abundant number, since it is smaller than the sum of its proper divisors (14984000).

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

13621780 is a wasteful number, since it uses less digits than its factorization.

13621780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681098 (or 681096 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 13621780 is about 3690.7695674480. The cubic root of 13621780 is about 238.8239923071.

The spelling of 13621780 in words is "thirteen million, six hundred twenty-one thousand, seven hundred eighty".