121958458399 has 4 divisors (see below), whose sum is σ = 124553319264. Its totient is φ = 119363597536.

The previous prime is 121958458397. The next prime is 121958458477. The reversal of 121958458399 is 993854859121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121958458399 - 2¹ = 121958458397 is a prime.

It is a super-2 number, since 2×121958458399² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121958458399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121958458397) 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, 1297430362 + ... + 1297430455.

It is an arithmetic number, because the mean of its divisors is an integer number (31138329816).

Almost surely, 2^121958458399 is an apocalyptic number.

121958458399 is a deficient number, since it is larger than the sum of its proper divisors (2594860865).

121958458399 is an equidigital number, since it uses as much as digits as its factorization.

121958458399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2594860864.

The product of its digits is 27993600, while the sum is 64.

The spelling of 121958458399 in words is "one hundred twenty-one billion, nine hundred fifty-eight million, four hundred fifty-eight thousand, three hundred ninety-nine".