121101021551 has 4 divisors (see below), whose sum is σ = 128224611072. Its totient is φ = 113977432032.

The previous prime is 121101021541. The next prime is 121101021593. The reversal of 121101021551 is 155120101121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155120101121 = 251 ⋅618008371.

It is a cyclic number.

It is not a de Polignac number, because 121101021551 - 2²⁶ = 121033912687 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 (121101021521) 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, 3561794735 + ... + 3561794768.

It is an arithmetic number, because the mean of its divisors is an integer number (32056152768).

Almost surely, 2^121101021551 is an apocalyptic number.

121101021551 is a deficient number, since it is larger than the sum of its proper divisors (7123589521).

121101021551 is an equidigital number, since it uses as much as digits as its factorization.

121101021551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7123589520.

The product of its (nonzero) digits is 100, while the sum is 20.

Adding to 121101021551 its reverse (155120101121), we get a palindrome (276221122672).

The spelling of 121101021551 in words is "one hundred twenty-one billion, one hundred one million, twenty-one thousand, five hundred fifty-one".