25561800421 has 8 divisors (see below), whose sum is σ = 26679401280. Its totient is φ = 24444717792.

The previous prime is 25561800401. The next prime is 25561800443. The reversal of 25561800421 is 12400816552.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25561800421 - 2¹¹ = 25561798373 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 (25561800401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27016 + ... + 227713.

It is an arithmetic number, because the mean of its divisors is an integer number (3334925160).

Almost surely, 2^25561800421 is an apocalyptic number.

It is an amenable number.

25561800421 is a deficient number, since it is larger than the sum of its proper divisors (1117600859).

25561800421 is a wasteful number, since it uses less digits than its factorization.

25561800421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259115.

The product of its (nonzero) digits is 19200, while the sum is 34.

The spelling of 25561800421 in words is "twenty-five billion, five hundred sixty-one million, eight hundred thousand, four hundred twenty-one".