121855191120 has 120 divisors (see below), whose sum is σ = 440709641736. Its totient is φ = 29995121664.

The previous prime is 121855191103. The next prime is 121855191131. The reversal of 121855191120 is 21191558121.

It is a happy number.

121855191120 is a `hidden beast` number, since 1 + 2 + 1 + 8 + 551 + 91 + 12 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 324864576 + 121530326544 = 18024^2 + 348612^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 6499999 + ... + 6518718.

Almost surely, 2^121855191120 is an apocalyptic number.

121855191120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121855191120 is an abundant number, since it is smaller than the sum of its proper divisors (318854450616).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121855191120 is a wasteful number, since it uses less digits than its factorization.

121855191120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13018749 (or 13018740 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 36.

The spelling of 121855191120 in words is "one hundred twenty-one billion, eight hundred fifty-five million, one hundred ninety-one thousand, one hundred twenty".