25891997 has 4 divisors (see below), whose sum is σ = 27017760. Its totient is φ = 24766236.

The previous prime is 25891991. The next prime is 25892017. The reversal of 25891997 is 79919852.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25891997 - 2¹⁴ = 25875613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25891991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 562847 + ... + 562892.

It is an arithmetic number, because the mean of its divisors is an integer number (6754440).

Almost surely, 2^25891997 is an apocalyptic number.

It is an amenable number.

25891997 is a deficient number, since it is larger than the sum of its proper divisors (1125763).

25891997 is a wasteful number, since it uses less digits than its factorization.

25891997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1125762.

The product of its digits is 408240, while the sum is 50.

The square root of 25891997 is about 5088.4179270182. The cubic root of 25891997 is about 295.8388343794.

The spelling of 25891997 in words is "twenty-five million, eight hundred ninety-one thousand, nine hundred ninety-seven".