121553553 has 32 divisors (see below), whose sum is σ = 188023680. Its totient is φ = 69032960.

The previous prime is 121553533. The next prime is 121553557. The reversal of 121553553 is 355355121.

It is a cyclic number.

It is not a de Polignac number, because 121553553 - 2⁵ = 121553521 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121553553.

It is not an unprimeable number, because it can be changed into a prime (121553557) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 217951 + ... + 218507.

It is an arithmetic number, because the mean of its divisors is an integer number (5875740).

Almost surely, 2^121553553 is an apocalyptic number.

It is an amenable number.

121553553 is a deficient number, since it is larger than the sum of its proper divisors (66470127).

121553553 is a wasteful number, since it uses less digits than its factorization.

121553553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 977.

The product of its digits is 11250, while the sum is 30.

The square root of 121553553 is about 11025.1327883160. The cubic root of 121553553 is about 495.3618454150.

The spelling of 121553553 in words is "one hundred twenty-one million, five hundred fifty-three thousand, five hundred fifty-three".