12620999797561 has 4 divisors (see below), whose sum is σ = 12621007011712. Its totient is φ = 12620992583412.

The previous prime is 12620999797543. The next prime is 12620999797573. The reversal of 12620999797561 is 16579799902621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 12620999797561 - 2¹³ = 12620999789369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12620999797531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 866800 + ... + 5098366.

It is an arithmetic number, because the mean of its divisors is an integer number (3155251752928).

Almost surely, 2^{12620999797561} is an apocalyptic number.

It is an amenable number.

12620999797561 is a deficient number, since it is larger than the sum of its proper divisors (7214151).

12620999797561 is an equidigital number, since it uses as much as digits as its factorization.

12620999797561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7214150.

The product of its (nonzero) digits is 231472080, while the sum is 73.

The spelling of 12620999797561 in words is "twelve trillion, six hundred twenty billion, nine hundred ninety-nine million, seven hundred ninety-seven thousand, five hundred sixty-one".