25278397 has 4 divisors (see below), whose sum is σ = 25583040. Its totient is φ = 24973756.

The previous prime is 25278389. The next prime is 25278431. The reversal of 25278397 is 79387252.

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 25278397 - 2³ = 25278389 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 (25278317) 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, 152197 + ... + 152362.

It is an arithmetic number, because the mean of its divisors is an integer number (6395760).

Almost surely, 2^25278397 is an apocalyptic number.

It is an amenable number.

25278397 is a deficient number, since it is larger than the sum of its proper divisors (304643).

25278397 is an equidigital number, since it uses as much as digits as its factorization.

25278397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304642.

The product of its digits is 211680, while the sum is 43.

The square root of 25278397 is about 5027.7626236727. The cubic root of 25278397 is about 293.4831533505.

The spelling of 25278397 in words is "twenty-five million, two hundred seventy-eight thousand, three hundred ninety-seven".