25139991 has 16 divisors (see below), whose sum is σ = 36078048. Its totient is φ = 15513600.

The previous prime is 25139969. The next prime is 25140007. The reversal of 25139991 is 19993152.

It is not a de Polignac number, because 25139991 - 2⁶ = 25139927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25139291) 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, 930 + ... + 7151.

It is an arithmetic number, because the mean of its divisors is an integer number (2254878).

Almost surely, 2^25139991 is an apocalyptic number.

25139991 is a deficient number, since it is larger than the sum of its proper divisors (10938057).

25139991 is a wasteful number, since it uses less digits than its factorization.

25139991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8162.

The product of its digits is 21870, while the sum is 39.

The square root of 25139991 is about 5013.9795571981. The cubic root of 25139991 is about 292.9465398082.

The spelling of 25139991 in words is "twenty-five million, one hundred thirty-nine thousand, nine hundred ninety-one".