128551723 has 4 divisors (see below), whose sum is σ = 130179040. Its totient is φ = 126924408.

The previous prime is 128551711. The next prime is 128551729. The reversal of 128551723 is 327155821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 327155821 = 139 ⋅2353639.

It is a cyclic number.

It is not a de Polignac number, because 128551723 - 2⁵ = 128551691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128551729) 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, 813540 + ... + 813697.

It is an arithmetic number, because the mean of its divisors is an integer number (32544760).

Almost surely, 2^128551723 is an apocalyptic number.

128551723 is a deficient number, since it is larger than the sum of its proper divisors (1627317).

128551723 is an equidigital number, since it uses as much as digits as its factorization.

128551723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1627316.

The product of its digits is 16800, while the sum is 34.

The square root of 128551723 is about 11338.0652229558. The cubic root of 128551723 is about 504.6914731475.

The spelling of 128551723 in words is "one hundred twenty-eight million, five hundred fifty-one thousand, seven hundred twenty-three".