12137981 has 2 divisors, whose sum is σ = 12137982. Its totient is φ = 12137980.

The previous prime is 12137969. The next prime is 12137989. The reversal of 12137981 is 18973121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10272025 + 1865956 = 3205^2 + 1366^2 .

It is a cyclic number.

It is not a de Polignac number, because 12137981 - 2¹⁸ = 11875837 is a prime.

It is a super-2 number, since 2×12137981² = 294661165512722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12137989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6068990 + 6068991.

It is an arithmetic number, because the mean of its divisors is an integer number (6068991).

Almost surely, 2^12137981 is an apocalyptic number.

It is an amenable number.

12137981 is a deficient number, since it is larger than the sum of its proper divisors (1).

12137981 is an equidigital number, since it uses as much as digits as its factorization.

12137981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 32.

The square root of 12137981 is about 3483.9605336456. The cubic root of 12137981 is about 229.8169999919.

The spelling of 12137981 in words is "twelve million, one hundred thirty-seven thousand, nine hundred eighty-one".