25561386478 has 8 divisors (see below), whose sum is σ = 38401897680. Its totient is φ = 12760753920.

The previous prime is 25561386457. The next prime is 25561386517. The reversal of 25561386478 is 87468316552.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 9968058 + ... + 9970621.

It is an arithmetic number, because the mean of its divisors is an integer number (4800237210).

Almost surely, 2^25561386478 is an apocalyptic number.

25561386478 is a deficient number, since it is larger than the sum of its proper divisors (12840511202).

25561386478 is a wasteful number, since it uses less digits than its factorization.

25561386478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19939322.

The product of its digits is 9676800, while the sum is 55.

The spelling of 25561386478 in words is "twenty-five billion, five hundred sixty-one million, three hundred eighty-six thousand, four hundred seventy-eight".