123581879969 has 2 divisors, whose sum is σ = 123581879970. Its totient is φ = 123581879968.

The previous prime is 123581879951. The next prime is 123581880011. The reversal of 123581879969 is 969978185321.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122211769744 + 1370110225 = 349588^2 + 37015^2 .

It is a cyclic number.

It is not a de Polignac number, because 123581879969 - 2⁸ = 123581879713 is a prime.

It is a super-2 number, since 2×123581879969² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 123581879899 and 123581879908.

It is not a weakly prime, because it can be changed into another prime (123581872969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61790939984 + 61790939985.

It is an arithmetic number, because the mean of its divisors is an integer number (61790939985).

Almost surely, 2^123581879969 is an apocalyptic number.

It is an amenable number.

123581879969 is a deficient number, since it is larger than the sum of its proper divisors (1).

123581879969 is an equidigital number, since it uses as much as digits as its factorization.

123581879969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58786560, while the sum is 68.

The spelling of 123581879969 in words is "one hundred twenty-three billion, five hundred eighty-one million, eight hundred seventy-nine thousand, nine hundred sixty-nine".