25128139 has 2 divisors, whose sum is σ = 25128140. Its totient is φ = 25128138.

The previous prime is 25128119. The next prime is 25128161. The reversal of 25128139 is 93182152.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25128139 - 2²³ = 16739531 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25128139.

It is not a weakly prime, because it can be changed into another prime (25128109) 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 as a sum of consecutive naturals, namely, 12564069 + 12564070.

It is an arithmetic number, because the mean of its divisors is an integer number (12564070).

Almost surely, 2^25128139 is an apocalyptic number.

25128139 is a deficient number, since it is larger than the sum of its proper divisors (1).

25128139 is an equidigital number, since it uses as much as digits as its factorization.

25128139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 31.

The square root of 25128139 is about 5012.7975223422. The cubic root of 25128139 is about 292.9004969894.

It can be divided in two parts, 25 and 128139, that added together give a square (128164 = 358²).

The spelling of 25128139 in words is "twenty-five million, one hundred twenty-eight thousand, one hundred thirty-nine".