123243502221551 has 4 divisors (see below), whose sum is σ = 123243527755704. Its totient is φ = 123243476687400.

The previous prime is 123243502221523. The next prime is 123243502221559. The reversal of 123243502221551 is 155122205342321.

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 123243502221551 - 2²⁶ = 123243435112687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123243502221559) 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, 3074165 + ... + 15998046.

It is an arithmetic number, because the mean of its divisors is an integer number (30810881938926).

Almost surely, 2^{123243502221551} is an apocalyptic number.

123243502221551 is a deficient number, since it is larger than the sum of its proper divisors (25534153).

123243502221551 is an equidigital number, since it uses as much as digits as its factorization.

123243502221551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25534152.

The product of its (nonzero) digits is 144000, while the sum is 38.

Adding to 123243502221551 its reverse (155122205342321), we get a palindrome (278365707563872).

The spelling of 123243502221551 in words is "one hundred twenty-three trillion, two hundred forty-three billion, five hundred two million, two hundred twenty-one thousand, five hundred fifty-one".