123421077921 has 4 divisors (see below), whose sum is σ = 164561437232. Its totient is φ = 82280718612.

The previous prime is 123421077917. The next prime is 123421077973. The reversal of 123421077921 is 129770124321.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 123421077921 - 2² = 123421077917 is a prime.

It is a super-4 number, since 4×123421077921⁴ (a number of 45 digits) contains 4444 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 123421077921.

It is not an unprimeable number, because it can be changed into a prime (123421077121) 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, 20570179651 + ... + 20570179656.

It is an arithmetic number, because the mean of its divisors is an integer number (41140359308).

Almost surely, 2^123421077921 is an apocalyptic number.

It is an amenable number.

123421077921 is a deficient number, since it is larger than the sum of its proper divisors (41140359311).

123421077921 is an equidigital number, since it uses as much as digits as its factorization.

123421077921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41140359310.

The product of its (nonzero) digits is 42336, while the sum is 39.

It can be divided in two parts, 1234210 and 77921, that added together give a palindrome (1312131).

The spelling of 123421077921 in words is "one hundred twenty-three billion, four hundred twenty-one million, seventy-seven thousand, nine hundred twenty-one".