25815619 has 2 divisors, whose sum is σ = 25815620. Its totient is φ = 25815618.

The previous prime is 25815617. The next prime is 25815649. The reversal of 25815619 is 91651852.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25815619 - 2¹ = 25815617 is a prime.

It is a super-2 number, since 2×25815619² = 1332892368706322, which contains 22 as substring.

Together with 25815617, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (25815613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12907809 + 12907810.

It is an arithmetic number, because the mean of its divisors is an integer number (12907810).

Almost surely, 2^25815619 is an apocalyptic number.

25815619 is a deficient number, since it is larger than the sum of its proper divisors (1).

25815619 is an equidigital number, since it uses as much as digits as its factorization.

25815619 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 37.

The square root of 25815619 is about 5080.9073008666. The cubic root of 25815619 is about 295.5476526039.

The spelling of 25815619 in words is "twenty-five million, eight hundred fifteen thousand, six hundred nineteen".