121979805 has 16 divisors (see below), whose sum is σ = 199321344. Its totient is φ = 63671360.

The previous prime is 121979783. The next prime is 121979807. The reversal of 121979805 is 508979121.

It is not a de Polignac number, because 121979805 - 2⁵ = 121979773 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121979807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85806 + ... + 87215.

It is an arithmetic number, because the mean of its divisors is an integer number (12457584).

Almost surely, 2^121979805 is an apocalyptic number.

121979805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121979805 is a deficient number, since it is larger than the sum of its proper divisors (77341539).

121979805 is a wasteful number, since it uses less digits than its factorization.

121979805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173076.

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

The square root of 121979805 is about 11044.4467946566. The cubic root of 121979805 is about 495.9401985763.

The spelling of 121979805 in words is "one hundred twenty-one million, nine hundred seventy-nine thousand, eight hundred five".