128199825 has 72 divisors (see below), whose sum is σ = 253551480. Its totient is φ = 61516800.

The previous prime is 128199811. The next prime is 128199829. The reversal of 128199825 is 528991821.

It can be written as a sum of positive squares in 12 ways, for example, as 94012416 + 34187409 = 9696^2 + 5847^2 .

It is not a de Polignac number, because 128199825 - 2⁴ = 128199809 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (128199829) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 119391 + ... + 120459.

Almost surely, 2^128199825 is an apocalyptic number.

128199825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

128199825 is a deficient number, since it is larger than the sum of its proper divisors (125351655).

128199825 is a wasteful number, since it uses less digits than its factorization.

128199825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1139 (or 1131 counting only the distinct ones).

The product of its digits is 103680, while the sum is 45.

The square root of 128199825 is about 11322.5361558266. The cubic root of 128199825 is about 504.2305374841.

The spelling of 128199825 in words is "one hundred twenty-eight million, one hundred ninety-nine thousand, eight hundred twenty-five".