121905879 has 8 divisors (see below), whose sum is σ = 168146160. Its totient is φ = 78468096.

The previous prime is 121905871. The next prime is 121905887. The reversal of 121905879 is 978509121.

It is an interprime number because it is at equal distance from previous prime (121905871) and next prime (121905887).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 121905879 - 2³ = 121905871 is a prime.

It is a super-2 number, since 2×121905879² = 29722086669525282, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 121905879.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121905871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 700522 + ... + 700695.

It is an arithmetic number, because the mean of its divisors is an integer number (21018270).

Almost surely, 2^121905879 is an apocalyptic number.

121905879 is a deficient number, since it is larger than the sum of its proper divisors (46240281).

121905879 is a wasteful number, since it uses less digits than its factorization.

121905879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1401249.

The product of its (nonzero) digits is 45360, while the sum is 42.

The square root of 121905879 is about 11041.0995376366. The cubic root of 121905879 is about 495.8399899553.

The spelling of 121905879 in words is "one hundred twenty-one million, nine hundred five thousand, eight hundred seventy-nine".