25557900221 has 16 divisors (see below), whose sum is σ = 29276848128. Its totient is φ = 21855970800.

The previous prime is 25557900209. The next prime is 25557900229. The reversal of 25557900221 is 12200975552.

It is a cyclic number.

It is not a de Polignac number, because 25557900221 - 2⁶ = 25557900157 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 (25557900229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10209656 + ... + 10212158.

It is an arithmetic number, because the mean of its divisors is an integer number (1829803008).

Almost surely, 2^25557900221 is an apocalyptic number.

It is an amenable number.

25557900221 is a deficient number, since it is larger than the sum of its proper divisors (3718947907).

25557900221 is a wasteful number, since it uses less digits than its factorization.

25557900221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5312.

The product of its (nonzero) digits is 63000, while the sum is 38.

The spelling of 25557900221 in words is "twenty-five billion, five hundred fifty-seven million, nine hundred thousand, two hundred twenty-one".