25851317994 has 40 divisors (see below), whose sum is σ = 57939388320. Its totient is φ = 8615129544.

The previous prime is 25851317993. The next prime is 25851318007. The reversal of 25851317994 is 49971315852.

It is a happy number.

25851317994 is a `hidden beast` number, since 2 + 58 + 513 + 1 + 79 + 9 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 25851317994.

It is not an unprimeable number, because it can be changed into a prime (25851317993) 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 in 19 ways as a sum of consecutive naturals, for example, 803787 + ... + 835329.

It is an arithmetic number, because the mean of its divisors is an integer number (1448484708).

Almost surely, 2^25851317994 is an apocalyptic number.

25851317994 is an abundant number, since it is smaller than the sum of its proper divisors (32088070326).

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

25851317994 is a wasteful number, since it uses less digits than its factorization.

25851317994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36616 (or 36607 counting only the distinct ones).

The product of its digits is 2721600, while the sum is 54.

The spelling of 25851317994 in words is "twenty-five billion, eight hundred fifty-one million, three hundred seventeen thousand, nine hundred ninety-four".