12621399025 has 9 divisors (see below), whose sum is σ = 15651231361. Its totient is φ = 10096669840.

The previous prime is 12621399023. The next prime is 12621399071. The reversal of 12621399025 is 52099312621.

The square root of 12621399025 is 112345.

It is a perfect power (a square), and thus also a powerful number.

12621399025 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 215003569 + 12406395456 = 14663^2 + 111384^2 .

It is not a de Polignac number, because 12621399025 - 2¹ = 12621399023 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12621399023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 550491 + ... + 572959.

Almost surely, 2^12621399025 is an apocalyptic number.

12621399025 is the 112345-th square number.

12621399025 is the 56173-rd centered octagonal number.

It is an amenable number.

12621399025 is a deficient number, since it is larger than the sum of its proper divisors (3029832336).

12621399025 is an frugal number, since it uses more digits than its factorization.

12621399025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44948 (or 22474 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 40.

The spelling of 12621399025 in words is "twelve billion, six hundred twenty-one million, three hundred ninety-nine thousand, twenty-five".