25219991 has 2 divisors, whose sum is σ = 25219992. Its totient is φ = 25219990.

The previous prime is 25219979. The next prime is 25220033. The reversal of 25219991 is 19991252.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25219991 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25215991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12609995 + 12609996.

It is an arithmetic number, because the mean of its divisors is an integer number (12609996).

Almost surely, 2^25219991 is an apocalyptic number.

25219991 is a deficient number, since it is larger than the sum of its proper divisors (1).

25219991 is an equidigital number, since it uses as much as digits as its factorization.

25219991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14580, while the sum is 38.

The square root of 25219991 is about 5021.9509157299. The cubic root of 25219991 is about 293.2569470810.

The spelling of 25219991 in words is "twenty-five million, two hundred nineteen thousand, nine hundred ninety-one".