121435551 has 16 divisors (see below), whose sum is σ = 180373600. Its totient is φ = 80745984.

The previous prime is 121435547. The next prime is 121435577. The reversal of 121435551 is 155534121.

It is not a de Polignac number, because 121435551 - 2² = 121435547 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121435541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5055 + ... + 16383.

It is an arithmetic number, because the mean of its divisors is an integer number (11273350).

Almost surely, 2^121435551 is an apocalyptic number.

121435551 is a deficient number, since it is larger than the sum of its proper divisors (58938049).

121435551 is a wasteful number, since it uses less digits than its factorization.

121435551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11735 (or 11729 counting only the distinct ones).

The product of its digits is 3000, while the sum is 27.

The square root of 121435551 is about 11019.7799887294. The cubic root of 121435551 is about 495.2014973969.

Adding to 121435551 its reverse (155534121), we get a palindrome (276969672).

The spelling of 121435551 in words is "one hundred twenty-one million, four hundred thirty-five thousand, five hundred fifty-one".