25128649 has 16 divisors (see below), whose sum is σ = 31046400. Its totient is φ = 19805760.

The previous prime is 25128647. The next prime is 25128667. The reversal of 25128649 is 94682152.

It is not a de Polignac number, because 25128649 - 2¹ = 25128647 is a prime.

Its product of digits (34560) is a multiple of the sum of its prime divisors (1080).

It is not an unprimeable number, because it can be changed into a prime (25128643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41652 + ... + 42250.

It is an arithmetic number, because the mean of its divisors is an integer number (1940400).

Almost surely, 2^25128649 is an apocalyptic number.

It is an amenable number.

25128649 is a deficient number, since it is larger than the sum of its proper divisors (5917751).

25128649 is a wasteful number, since it uses less digits than its factorization.

25128649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080.

The product of its digits is 34560, while the sum is 37.

The square root of 25128649 is about 5012.8483918826. The cubic root of 25128649 is about 292.9024785428.

It can be divided in two parts, 251 and 28649, that added together give a square (28900 = 170²).

The spelling of 25128649 in words is "twenty-five million, one hundred twenty-eight thousand, six hundred forty-nine".