25553210161581 has 12 divisors (see below), whose sum is σ = 36922018895580. Its totient is φ = 17030015084160.

The previous prime is 25553210161513. The next prime is 25553210161607. The reversal of 25553210161581 is 18516101235552.

25553210161581 is a `hidden beast` number, since 2 + 5 + 5 + 5 + 3 + 2 + 1 + 0 + 1 + 61 + 581 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1382870162025 + 24170339999556 = 1175955^2 + 4916334^2 .

It is not a de Polignac number, because 25553210161581 - 2¹³ = 25553210153389 is a prime.

It is a super-2 number, since 2×25553210161581² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25553210161481) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 454833426 + ... + 454889603.

It is an arithmetic number, because the mean of its divisors is an integer number (3076834907965).

Almost surely, 2^{25553210161581} is an apocalyptic number.

It is an amenable number.

25553210161581 is a deficient number, since it is larger than the sum of its proper divisors (11368808733999).

25553210161581 is a wasteful number, since it uses less digits than its factorization.

25553210161581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 909726156 (or 909726153 counting only the distinct ones).

The product of its (nonzero) digits is 360000, while the sum is 45.

The spelling of 25553210161581 in words is "twenty-five trillion, five hundred fifty-three billion, two hundred ten million, one hundred sixty-one thousand, five hundred eighty-one".