25751081666 has 4 divisors (see below), whose sum is σ = 38626622502. Its totient is φ = 12875540832.

The previous prime is 25751081627. The next prime is 25751081669. The reversal of 25751081666 is 66618015752.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15470135641 + 10280946025 = 124379^2 + 101395^2 .

It is a super-3 number, since 3×25751081666³ (a number of 32 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 25751081666.

It is not an unprimeable number, because it can be changed into a prime (25751081669) by changing a digit.

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 as a sum of consecutive naturals, namely, 6437770415 + ... + 6437770418.

Almost surely, 2^25751081666 is an apocalyptic number.

25751081666 is a deficient number, since it is larger than the sum of its proper divisors (12875540836).

25751081666 is a wasteful number, since it uses less digits than its factorization.

25751081666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12875540835.

The product of its (nonzero) digits is 604800, while the sum is 47.

The spelling of 25751081666 in words is "twenty-five billion, seven hundred fifty-one million, eighty-one thousand, six hundred sixty-six".