1231972979 has 4 divisors (see below), whose sum is σ = 1265269584. Its totient is φ = 1198676376.

The previous prime is 1231972967. The next prime is 1231972991. The reversal of 1231972979 is 9792791321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9792791321 = 68261 ⋅143461.

It is an interprime number because it is at equal distance from previous prime (1231972967) and next prime (1231972991).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231972979 is a prime.

It is a super-2 number, since 2×1231972979² = 3035514841972268882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231972909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16648247 + ... + 16648320.

It is an arithmetic number, because the mean of its divisors is an integer number (316317396).

Almost surely, 2^1231972979 is an apocalyptic number.

1231972979 is a deficient number, since it is larger than the sum of its proper divisors (33296605).

1231972979 is an equidigital number, since it uses as much as digits as its factorization.

1231972979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33296604.

The product of its digits is 428652, while the sum is 50.

The square root of 1231972979 is about 35099.4726313658. The cubic root of 1231972979 is about 1072.0138447175.

The spelling of 1231972979 in words is "one billion, two hundred thirty-one million, nine hundred seventy-two thousand, nine hundred seventy-nine".