12721261437 has 8 divisors (see below), whose sum is σ = 18846313280. Its totient is φ = 8480840940.

The previous prime is 12721261411. The next prime is 12721261471. The reversal of 12721261437 is 73416212721.

12721261437 is a `hidden beast` number, since 1 + 2 + 7 + 2 + 1 + 2 + 614 + 37 = 666.

It is not a de Polignac number, because 12721261437 - 2⁷ = 12721261309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12721261477) 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, 235578889 + ... + 235578942.

It is an arithmetic number, because the mean of its divisors is an integer number (2355789160).

Almost surely, 2^12721261437 is an apocalyptic number.

It is an amenable number.

12721261437 is a deficient number, since it is larger than the sum of its proper divisors (6125051843).

12721261437 is an equidigital number, since it uses as much as digits as its factorization.

12721261437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471157840 (or 471157834 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The spelling of 12721261437 in words is "twelve billion, seven hundred twenty-one million, two hundred sixty-one thousand, four hundred thirty-seven".