12491612661 has 16 divisors (see below), whose sum is σ = 18660691008. Its totient is φ = 7366060800.

The previous prime is 12491612629. The next prime is 12491612687. The reversal of 12491612661 is 16621619421.

It is not a de Polignac number, because 12491612661 - 2⁵ = 12491612629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12491612261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5114100 + ... + 5116541.

It is an arithmetic number, because the mean of its divisors is an integer number (1166293188).

Almost surely, 2^12491612661 is an apocalyptic number.

12491612661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12491612661 is a deficient number, since it is larger than the sum of its proper divisors (6169078347).

12491612661 is a wasteful number, since it uses less digits than its factorization.

12491612661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10230692.

The product of its digits is 31104, while the sum is 39.

The spelling of 12491612661 in words is "twelve billion, four hundred ninety-one million, six hundred twelve thousand, six hundred sixty-one".