25518404623 has 4 divisors (see below), whose sum is σ = 26398349640. Its totient is φ = 24638459608.

The previous prime is 25518404521. The next prime is 25518404627. The reversal of 25518404623 is 32640481552.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 25518404623 - 2⁹ = 25518404111 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 (25518404627) 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, 439972465 + ... + 439972522.

It is an arithmetic number, because the mean of its divisors is an integer number (6599587410).

Almost surely, 2^25518404623 is an apocalyptic number.

25518404623 is a deficient number, since it is larger than the sum of its proper divisors (879945017).

25518404623 is an equidigital number, since it uses as much as digits as its factorization.

25518404623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 879945016.

The product of its (nonzero) digits is 230400, while the sum is 40.

The spelling of 25518404623 in words is "twenty-five billion, five hundred eighteen million, four hundred four thousand, six hundred twenty-three".