128990818623 has 4 divisors (see below), whose sum is σ = 171987758168. Its totient is φ = 85993879080.

The previous prime is 128990818577. The next prime is 128990818669. The reversal of 128990818623 is 326818099821.

It is a happy number.

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 (128990818577) and next prime (128990818669).

It is not a de Polignac number, because 128990818623 - 2⁸ = 128990818367 is a prime.

It is a super-2 number, since 2×128990818623² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128990819623) 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, 21498469768 + ... + 21498469773.

It is an arithmetic number, because the mean of its divisors is an integer number (42996939542).

Almost surely, 2^128990818623 is an apocalyptic number.

128990818623 is a deficient number, since it is larger than the sum of its proper divisors (42996939545).

128990818623 is an equidigital number, since it uses as much as digits as its factorization.

128990818623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42996939544.

The product of its (nonzero) digits is 2985984, while the sum is 57.

The spelling of 128990818623 in words is "one hundred twenty-eight billion, nine hundred ninety million, eight hundred eighteen thousand, six hundred twenty-three".