121919899 has 4 divisors (see below), whose sum is σ = 122247136. Its totient is φ = 121592664.

The previous prime is 121919893. The next prime is 121919909. The reversal of 121919899 is 998919121.

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 121919899 - 2¹⁵ = 121887131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121919893) 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, 163059 + ... + 163804.

It is an arithmetic number, because the mean of its divisors is an integer number (30561784).

Almost surely, 2^121919899 is an apocalyptic number.

121919899 is a deficient number, since it is larger than the sum of its proper divisors (327237).

121919899 is an equidigital number, since it uses as much as digits as its factorization.

121919899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327236.

The product of its digits is 104976, while the sum is 49.

The square root of 121919899 is about 11041.7344199179. The cubic root of 121919899 is about 495.8589975433.

It can be divided in two parts, 12191989 and 9, that multiplied together give a palindrome (109727901).

The spelling of 121919899 in words is "one hundred twenty-one million, nine hundred nineteen thousand, eight hundred ninety-nine".