121899381 has 4 divisors (see below), whose sum is σ = 162532512. Its totient is φ = 81266252.

The previous prime is 121899377. The next prime is 121899389. The reversal of 121899381 is 183998121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121899381 - 2² = 121899377 is a prime.

It is a super-2 number, since 2×121899381² = 29718918176366322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121899389) 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, 20316561 + ... + 20316566.

It is an arithmetic number, because the mean of its divisors is an integer number (40633128).

Almost surely, 2^121899381 is an apocalyptic number.

It is an amenable number.

121899381 is a deficient number, since it is larger than the sum of its proper divisors (40633131).

121899381 is an equidigital number, since it uses as much as digits as its factorization.

121899381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40633130.

The product of its digits is 31104, while the sum is 42.

The square root of 121899381 is about 11040.8052695444. The cubic root of 121899381 is about 495.8311798100.

The spelling of 121899381 in words is "one hundred twenty-one million, eight hundred ninety-nine thousand, three hundred eighty-one".