12537737221 has 4 divisors (see below), whose sum is σ = 12543741100. Its totient is φ = 12531733344.

The previous prime is 12537737209. The next prime is 12537737227. The reversal of 12537737221 is 12273773521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12273773521 = 23 ⋅533642327.

It can be written as a sum of positive squares in 2 ways, for example, as 5758684996 + 6779052225 = 75886^2 + 82335^2 .

It is a cyclic number.

It is not a de Polignac number, because 12537737221 - 2¹⁵ = 12537704453 is a prime.

It is a super-3 number, since 3×12537737221³ (a number of 31 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12537737227) 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, 2998806 + ... + 3002983.

It is an arithmetic number, because the mean of its divisors is an integer number (3135935275).

Almost surely, 2^12537737221 is an apocalyptic number.

It is an amenable number.

12537737221 is a deficient number, since it is larger than the sum of its proper divisors (6003879).

12537737221 is an equidigital number, since it uses as much as digits as its factorization.

12537737221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6003878.

The product of its digits is 123480, while the sum is 40.

The spelling of 12537737221 in words is "twelve billion, five hundred thirty-seven million, seven hundred thirty-seven thousand, two hundred twenty-one".