25206557766 has 64 divisors (see below), whose sum is σ = 55991280576. Its totient is φ = 7514726400.

The previous prime is 25206557699. The next prime is 25206557771. The reversal of 25206557766 is 66775560252.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 677406 + ... + 713646.

It is an arithmetic number, because the mean of its divisors is an integer number (874863759).

Almost surely, 2^25206557766 is an apocalyptic number.

25206557766 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 25206557766, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27995640288).

25206557766 is an abundant number, since it is smaller than the sum of its proper divisors (30784722810).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25206557766 is a wasteful number, since it uses less digits than its factorization.

25206557766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36537.

The product of its (nonzero) digits is 5292000, while the sum is 51.

The spelling of 25206557766 in words is "twenty-five billion, two hundred six million, five hundred fifty-seven thousand, seven hundred sixty-six".