121591855 has 32 divisors (see below), whose sum is σ = 186375168. Its totient is φ = 73939200.

The previous prime is 121591843. The next prime is 121591859. The reversal of 121591855 is 558195121.

It is not a de Polignac number, because 121591855 - 2²⁵ = 88037423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121591859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11934 + ... + 19636.

It is an arithmetic number, because the mean of its divisors is an integer number (5824224).

Almost surely, 2^121591855 is an apocalyptic number.

121591855 is a deficient number, since it is larger than the sum of its proper divisors (64783313).

121591855 is a wasteful number, since it uses less digits than its factorization.

121591855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7767.

The product of its digits is 18000, while the sum is 37.

The square root of 121591855 is about 11026.8696827341. The cubic root of 121591855 is about 495.4138701027.

The spelling of 121591855 in words is "one hundred twenty-one million, five hundred ninety-one thousand, eight hundred fifty-five".