121199999999 has 4 divisors (see below), whose sum is σ = 130523076936. Its totient is φ = 111876923064.

The previous prime is 121199999981. The next prime is 121200000023. The reversal of 121199999999 is 999999991121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121199999999 - 2²⁸ = 120931564543 is a prime.

It is a Duffinian number.

121199999999 is a modest number, since divided by 999999 gives 121199 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121199999939) 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, 4661538449 + ... + 4661538474.

It is an arithmetic number, because the mean of its divisors is an integer number (32630769234).

Almost surely, 2^121199999999 is an apocalyptic number.

121199999999 is a deficient number, since it is larger than the sum of its proper divisors (9323076937).

121199999999 is an equidigital number, since it uses as much as digits as its factorization.

121199999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9323076936.

The product of its digits is 86093442, while the sum is 77.

The spelling of 121199999999 in words is "one hundred twenty-one billion, one hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".