25478216866 has 4 divisors (see below), whose sum is σ = 38217325302. Its totient is φ = 12739108432.

The previous prime is 25478216861. The next prime is 25478216867. The reversal of 25478216866 is 66861287452.

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., 16026294025 + 9451922841 = 126595^2 + 97221^2 .

It is not an unprimeable number, because it can be changed into a prime (25478216861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6369554215 + ... + 6369554218.

Almost surely, 2^25478216866 is an apocalyptic number.

25478216866 is a deficient number, since it is larger than the sum of its proper divisors (12739108436).

25478216866 is a wasteful number, since it uses less digits than its factorization.

25478216866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12739108435.

The product of its digits is 7741440, while the sum is 55.

The spelling of 25478216866 in words is "twenty-five billion, four hundred seventy-eight million, two hundred sixteen thousand, eight hundred sixty-six".