128872749 has 16 divisors (see below), whose sum is σ = 180623232. Its totient is φ = 81573888.

The previous prime is 128872741. The next prime is 128872753. The reversal of 128872749 is 947278821.

It is not a de Polignac number, because 128872749 - 2³ = 128872741 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128872698 and 128872707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128872741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2637 + ... + 16269.

It is an arithmetic number, because the mean of its divisors is an integer number (11288952).

Almost surely, 2^128872749 is an apocalyptic number.

It is an amenable number.

128872749 is a deficient number, since it is larger than the sum of its proper divisors (51750483).

128872749 is a wasteful number, since it uses less digits than its factorization.

128872749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13796.

The product of its digits is 451584, while the sum is 48.

The square root of 128872749 is about 11352.2133965144. The cubic root of 128872749 is about 505.1112377901. Note that the first 3 decimals are identical.

The spelling of 128872749 in words is "one hundred twenty-eight million, eight hundred seventy-two thousand, seven hundred forty-nine".