121533553111 has 4 divisors (see below), whose sum is σ = 121555994112. Its totient is φ = 121511112112.

The previous prime is 121533553091. The next prime is 121533553139. The reversal of 121533553111 is 111355335121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 111355335121 = 34537 ⋅3224233.

It is a cyclic number.

It is not a de Polignac number, because 121533553111 - 2⁹ = 121533552599 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 (121533550111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11212375 + ... + 11223208.

It is an arithmetic number, because the mean of its divisors is an integer number (30388998528).

Almost surely, 2^121533553111 is an apocalyptic number.

121533553111 is a deficient number, since it is larger than the sum of its proper divisors (22441001).

121533553111 is an equidigital number, since it uses as much as digits as its factorization.

121533553111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22441000.

The product of its digits is 6750, while the sum is 31.

Adding to 121533553111 its reverse (111355335121), we get a palindrome (232888888232).

The spelling of 121533553111 in words is "one hundred twenty-one billion, five hundred thirty-three million, five hundred fifty-three thousand, one hundred eleven".