25661851 has 4 divisors (see below), whose sum is σ = 25673704. Its totient is φ = 25650000.

The previous prime is 25661849. The next prime is 25661869. The reversal of 25661851 is 15816652.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 25661851 - 2¹ = 25661849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25661821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1650 + ... + 7351.

It is an arithmetic number, because the mean of its divisors is an integer number (6418426).

Almost surely, 2^25661851 is an apocalyptic number.

25661851 is a deficient number, since it is larger than the sum of its proper divisors (11853).

25661851 is an equidigital number, since it uses as much as digits as its factorization.

25661851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11852.

The product of its digits is 14400, while the sum is 34.

The square root of 25661851 is about 5065.7527574883. The cubic root of 25661851 is about 294.9596842349.

The spelling of 25661851 in words is "twenty-five million, six hundred sixty-one thousand, eight hundred fifty-one".