121551521 has 16 divisors (see below), whose sum is σ = 150019968. Its totient is φ = 95904000.

The previous prime is 121551517. The next prime is 121551553. The reversal of 121551521 is 125155121.

It is a cyclic number.

It is not a de Polignac number, because 121551521 - 2² = 121551517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121551821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34826 + ... + 38156.

It is an arithmetic number, because the mean of its divisors is an integer number (9376248).

Almost surely, 2^121551521 is an apocalyptic number.

It is an amenable number.

121551521 is a deficient number, since it is larger than the sum of its proper divisors (28468447).

121551521 is a wasteful number, since it uses less digits than its factorization.

121551521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3752.

The product of its digits is 500, while the sum is 23.

The square root of 121551521 is about 11025.0406348458. The cubic root of 121551521 is about 495.3590850929.

The spelling of 121551521 in words is "one hundred twenty-one million, five hundred fifty-one thousand, five hundred twenty-one".