121255551 has 6 divisors (see below), whose sum is σ = 175146920. Its totient is φ = 80837028.

The previous prime is 121255523. The next prime is 121255559. The reversal of 121255551 is 155552121.

It is not a de Polignac number, because 121255551 - 2⁶ = 121255487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121255559) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6736411 + ... + 6736428.

Almost surely, 2^121255551 is an apocalyptic number.

121255551 is a deficient number, since it is larger than the sum of its proper divisors (53891369).

121255551 is a wasteful number, since it uses less digits than its factorization.

121255551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13472845 (or 13472842 counting only the distinct ones).

The product of its digits is 2500, while the sum is 27.

The square root of 121255551 is about 11011.6098278136. The cubic root of 121255551 is about 494.9567026714.

The spelling of 121255551 in words is "one hundred twenty-one million, two hundred fifty-five thousand, five hundred fifty-one".