128525251 has 4 divisors (see below), whose sum is σ = 130073832. Its totient is φ = 126976672.

The previous prime is 128525239. The next prime is 128525261. The reversal of 128525251 is 152525821.

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

It is a cyclic number.

It is not a de Polignac number, because 128525251 - 2¹¹ = 128523203 is a prime.

It is a super-2 number, since 2×128525251² = 33037480289226002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128525261) 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, 774166 + ... + 774331.

It is an arithmetic number, because the mean of its divisors is an integer number (32518458).

Almost surely, 2^128525251 is an apocalyptic number.

128525251 is a deficient number, since it is larger than the sum of its proper divisors (1548581).

128525251 is an equidigital number, since it uses as much as digits as its factorization.

128525251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1548580.

The product of its digits is 8000, while the sum is 31.

The square root of 128525251 is about 11336.8977679081. The cubic root of 128525251 is about 504.6568279231.

The spelling of 128525251 in words is "one hundred twenty-eight million, five hundred twenty-five thousand, two hundred fifty-one".