12491377921 has 8 divisors (see below), whose sum is σ = 13641796800. Its totient is φ = 11343432240.

The previous prime is 12491377919. The next prime is 12491377937. The reversal of 12491377921 is 12977319421.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12491377921 - 2¹ = 12491377919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12491377621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 607726 + ... + 627943.

It is an arithmetic number, because the mean of its divisors is an integer number (1705224600).

Almost surely, 2^12491377921 is an apocalyptic number.

12491377921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12491377921 is a deficient number, since it is larger than the sum of its proper divisors (1150418879).

12491377921 is a wasteful number, since it uses less digits than its factorization.

12491377921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1236599.

The product of its digits is 190512, while the sum is 46.

The spelling of 12491377921 in words is "twelve billion, four hundred ninety-one million, three hundred seventy-seven thousand, nine hundred twenty-one".