12621556020 has 48 divisors (see below), whose sum is σ = 35766158400. Its totient is φ = 3325195776.

The previous prime is 12621556009. The next prime is 12621556043. The reversal of 12621556020 is 2065512621.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 1262245 + ... + 1272204.

It is an arithmetic number, because the mean of its divisors is an integer number (745128300).

Almost surely, 2^12621556020 is an apocalyptic number.

12621556020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12621556020 is an abundant number, since it is smaller than the sum of its proper divisors (23144602380).

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

12621556020 is a wasteful number, since it uses less digits than its factorization.

12621556020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2534544 (or 2534542 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 12621556020 in words is "twelve billion, six hundred twenty-one million, five hundred fifty-six thousand, twenty".