1232399981 has 2 divisors, whose sum is σ = 1232399982. Its totient is φ = 1232399980.

The previous prime is 1232399977. The next prime is 1232400041. The reversal of 1232399981 is 1899932321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 893471881 + 338928100 = 29891^2 + 18410^2 .

It is a cyclic number.

It is not a de Polignac number, because 1232399981 - 2² = 1232399977 is a prime.

It is a super-2 number, since 2×1232399981² = 3037619426337600722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1232399941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 616199990 + 616199991.

It is an arithmetic number, because the mean of its divisors is an integer number (616199991).

Almost surely, 2^1232399981 is an apocalyptic number.

It is an amenable number.

1232399981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1232399981 is an equidigital number, since it uses as much as digits as its factorization.

1232399981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209952, while the sum is 47.

The square root of 1232399981 is about 35105.5548453518. The cubic root of 1232399981 is about 1072.1376837919.

The spelling of 1232399981 in words is "one billion, two hundred thirty-two million, three hundred ninety-nine thousand, nine hundred eighty-one".