25991563 has 8 divisors (see below), whose sum is σ = 29464400. Its totient is φ = 22729248.

The previous prime is 25991561. The next prime is 25991591. The reversal of 25991563 is 36519952.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25991563 - 2¹ = 25991561 is a prime.

It is a super-2 number, since 2×25991563² = 1351122694365938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25991561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52368 + ... + 52861.

It is an arithmetic number, because the mean of its divisors is an integer number (3683050).

Almost surely, 2^25991563 is an apocalyptic number.

25991563 is a deficient number, since it is larger than the sum of its proper divisors (3472837).

25991563 is a wasteful number, since it uses less digits than its factorization.

25991563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105261.

The product of its digits is 72900, while the sum is 40.

The square root of 25991563 is about 5098.1921305498. The cubic root of 25991563 is about 296.2175590415.

The spelling of 25991563 in words is "twenty-five million, nine hundred ninety-one thousand, five hundred sixty-three".