25853658821 has 4 divisors (see below), whose sum is σ = 25854070944. Its totient is φ = 25853246700.

The previous prime is 25853658781. The next prime is 25853658847. The reversal of 25853658821 is 12885635852.

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 25853658821 - 2²² = 25849464517 is a prime.

It is a super-2 number, since 2×25853658821² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25853658881) 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, 90275 + ... + 244656.

It is an arithmetic number, because the mean of its divisors is an integer number (6463517736).

Almost surely, 2^25853658821 is an apocalyptic number.

It is an amenable number.

25853658821 is a deficient number, since it is larger than the sum of its proper divisors (412123).

25853658821 is an equidigital number, since it uses as much as digits as its factorization.

25853658821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412122.

The product of its digits is 4608000, while the sum is 53.

The spelling of 25853658821 in words is "twenty-five billion, eight hundred fifty-three million, six hundred fifty-eight thousand, eight hundred twenty-one".