121405518855 has 48 divisors (see below), whose sum is σ = 211618671264. Its totient is φ = 64386662400.

The previous prime is 121405518847. The next prime is 121405518877. The reversal of 121405518855 is 558815504121.

121405518855 is a `hidden beast` number, since 1 + 2 + 1 + 40 + 551 + 8 + 8 + 55 = 666.

It is not a de Polignac number, because 121405518855 - 2³ = 121405518847 is a prime.

It is a super-2 number, since 2×121405518855² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 121405518855.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6941832 + ... + 6959298.

It is an arithmetic number, because the mean of its divisors is an integer number (4408722318).

Almost surely, 2^121405518855 is an apocalyptic number.

121405518855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121405518855 is a deficient number, since it is larger than the sum of its proper divisors (90213152409).

121405518855 is a wasteful number, since it uses less digits than its factorization.

121405518855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18336 (or 18333 counting only the distinct ones).

The product of its (nonzero) digits is 320000, while the sum is 45.

The spelling of 121405518855 in words is "one hundred twenty-one billion, four hundred five million, five hundred eighteen thousand, eight hundred fifty-five".