25661497 has 4 divisors (see below), whose sum is σ = 26258320. Its totient is φ = 25064676.

The previous prime is 25661479. The next prime is 25661501. The reversal of 25661497 is 79416652.

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 25661497 - 2⁷ = 25661369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25661407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 298347 + ... + 298432.

It is an arithmetic number, because the mean of its divisors is an integer number (6564580).

Almost surely, 2^25661497 is an apocalyptic number.

It is an amenable number.

25661497 is a deficient number, since it is larger than the sum of its proper divisors (596823).

25661497 is an equidigital number, since it uses as much as digits as its factorization.

25661497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596822.

The product of its digits is 90720, while the sum is 40.

The square root of 25661497 is about 5065.7178168548. The cubic root of 25661497 is about 294.9583279258.

The spelling of 25661497 in words is "twenty-five million, six hundred sixty-one thousand, four hundred ninety-seven".