25545516778 has 32 divisors (see below), whose sum is σ = 39423960576. Its totient is φ = 12410713728.

The previous prime is 25545516767. The next prime is 25545516793. The reversal of 25545516778 is 87761554552.

It is a happy 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 15 ways as a sum of consecutive naturals, for example, 2958175 + ... + 2966797.

It is an arithmetic number, because the mean of its divisors is an integer number (1231998768).

Almost surely, 2^25545516778 is an apocalyptic number.

25545516778 is a deficient number, since it is larger than the sum of its proper divisors (13878443798).

25545516778 is a wasteful number, since it uses less digits than its factorization.

25545516778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8998.

The product of its digits is 11760000, while the sum is 55.

The spelling of 25545516778 in words is "twenty-five billion, five hundred forty-five million, five hundred sixteen thousand, seven hundred seventy-eight".