123344515551 has 4 divisors (see below), whose sum is σ = 164459354072. Its totient is φ = 82229677032.

The previous prime is 123344515543. The next prime is 123344515559. The reversal of 123344515551 is 155515443321.

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

It is an interprime number because it is at equal distance from previous prime (123344515543) and next prime (123344515559).

It is not a de Polignac number, because 123344515551 - 2³ = 123344515543 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 (123344515559) 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, 20557419256 + ... + 20557419261.

It is an arithmetic number, because the mean of its divisors is an integer number (41114838518).

Almost surely, 2^123344515551 is an apocalyptic number.

123344515551 is a deficient number, since it is larger than the sum of its proper divisors (41114838521).

123344515551 is an equidigital number, since it uses as much as digits as its factorization.

123344515551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41114838520.

The product of its digits is 180000, while the sum is 39.

Adding to 123344515551 its reverse (155515443321), we get a palindrome (278859958872).

The spelling of 123344515551 in words is "one hundred twenty-three billion, three hundred forty-four million, five hundred fifteen thousand, five hundred fifty-one".