121919805 has 24 divisors (see below), whose sum is σ = 241517952. Its totient is φ = 55734624.

The previous prime is 121919797. The next prime is 121919821. The reversal of 121919805 is 508919121.

It is not a de Polignac number, because 121919805 - 2³ = 121919797 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 121919805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 193209 + ... + 193838.

It is an arithmetic number, because the mean of its divisors is an integer number (10063248).

Almost surely, 2^121919805 is an apocalyptic number.

121919805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121919805 is a deficient number, since it is larger than the sum of its proper divisors (119598147).

121919805 is a wasteful number, since it uses less digits than its factorization.

121919805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387065 (or 387062 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 36.

The square root of 121919805 is about 11041.7301633394. The cubic root of 121919805 is about 495.8588701078.

The spelling of 121919805 in words is "one hundred twenty-one million, nine hundred nineteen thousand, eight hundred five".