121361718591 has 36 divisors (see below), whose sum is σ = 189180901728. Its totient is φ = 74711500032.

The previous prime is 121361718551. The next prime is 121361718593. The reversal of 121361718591 is 195817163121.

121361718591 is a `hidden beast` number, since 1 + 2 + 1 + 36 + 17 + 18 + 591 = 666.

It is not a de Polignac number, because 121361718591 - 2²³ = 121353329983 is a prime.

It is a super-2 number, since 2×121361718591² (a number of 23 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121361718593) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 288586 + ... + 570968.

It is an arithmetic number, because the mean of its divisors is an integer number (5255025048).

Almost surely, 2^121361718591 is an apocalyptic number.

121361718591 is a deficient number, since it is larger than the sum of its proper divisors (67819183137).

121361718591 is a wasteful number, since it uses less digits than its factorization.

121361718591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282512 (or 282456 counting only the distinct ones).

The product of its digits is 90720, while the sum is 45.

The spelling of 121361718591 in words is "one hundred twenty-one billion, three hundred sixty-one million, seven hundred eighteen thousand, five hundred ninety-one".