121454215551 has 24 divisors (see below), whose sum is σ = 181711211136. Its totient is φ = 78090073920.

The previous prime is 121454215529. The next prime is 121454215559. The reversal of 121454215551 is 155512454121.

121454215551 is a `hidden beast` number, since 1 + 2 + 1 + 454 + 2 + 155 + 51 = 666.

It is not a de Polignac number, because 121454215551 - 2³¹ = 119306731903 is a prime.

It is a super-2 number, since 2×121454215551² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121454215559) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 661120 + ... + 824613.

It is an arithmetic number, because the mean of its divisors is an integer number (7571300464).

Almost surely, 2^121454215551 is an apocalyptic number.

121454215551 is a deficient number, since it is larger than the sum of its proper divisors (60256995585).

121454215551 is a wasteful number, since it uses less digits than its factorization.

121454215551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1486063 (or 1486060 counting only the distinct ones).

The product of its digits is 40000, while the sum is 36.

Adding to 121454215551 its reverse (155512454121), we get a palindrome (276966669672).

The spelling of 121454215551 in words is "one hundred twenty-one billion, four hundred fifty-four million, two hundred fifteen thousand, five hundred fifty-one".