25660040421 has 4 divisors (see below), whose sum is σ = 34213387232. Its totient is φ = 17106693612.

The previous prime is 25660040383. The next prime is 25660040437. The reversal of 25660040421 is 12404006652.

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 not a de Polignac number, because 25660040421 - 2⁷ = 25660040293 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 (25660045421) 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, 4276673401 + ... + 4276673406.

It is an arithmetic number, because the mean of its divisors is an integer number (8553346808).

Almost surely, 2^25660040421 is an apocalyptic number.

It is an amenable number.

25660040421 is a deficient number, since it is larger than the sum of its proper divisors (8553346811).

25660040421 is an equidigital number, since it uses as much as digits as its factorization.

25660040421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8553346810.

The product of its (nonzero) digits is 11520, while the sum is 30.

The spelling of 25660040421 in words is "twenty-five billion, six hundred sixty million, forty thousand, four hundred twenty-one".