25555218166 has 16 divisors (see below), whose sum is σ = 40004179200. Its totient is φ = 12220622568.

The previous prime is 25555218137. The next prime is 25555218167. The reversal of 25555218166 is 66181255552.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25555218167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 434125 + ... + 489463.

It is an arithmetic number, because the mean of its divisors is an integer number (2500261200).

Almost surely, 2^25555218166 is an apocalyptic number.

25555218166 is a deficient number, since it is larger than the sum of its proper divisors (14448961034).

25555218166 is a wasteful number, since it uses less digits than its factorization.

25555218166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65403.

The product of its digits is 720000, while the sum is 46.

The spelling of 25555218166 in words is "twenty-five billion, five hundred fifty-five million, two hundred eighteen thousand, one hundred sixty-six".