25128971 has 4 divisors (see below), whose sum is σ = 28718832. Its totient is φ = 21539112.

The previous prime is 25128947. The next prime is 25128977. The reversal of 25128971 is 17982152.

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

It is a de Polignac number, because none of the positive numbers 2^k-25128971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25128977) 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, 1794920 + ... + 1794933.

It is an arithmetic number, because the mean of its divisors is an integer number (7179708).

Almost surely, 2^25128971 is an apocalyptic number.

25128971 is a deficient number, since it is larger than the sum of its proper divisors (3589861).

25128971 is an equidigital number, since it uses as much as digits as its factorization.

25128971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3589860.

The product of its digits is 10080, while the sum is 35.

The square root of 25128971 is about 5012.8805092482. The cubic root of 25128971 is about 292.9037296273.

The spelling of 25128971 in words is "twenty-five million, one hundred twenty-eight thousand, nine hundred seventy-one".