251603666066 has 16 divisors (see below), whose sum is σ = 403198337760. Its totient is φ = 117401866560.

The previous prime is 251603666059. The next prime is 251603666129. The reversal of 251603666066 is 660666306152.

251603666066 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 251603666066.

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 7 ways as a sum of consecutive naturals, for example, 49409015 + ... + 49414106.

It is an arithmetic number, because the mean of its divisors is an integer number (25199896110).

Almost surely, 2^251603666066 is an apocalyptic number.

251603666066 is a deficient number, since it is larger than the sum of its proper divisors (151594671694).

251603666066 is a wasteful number, since it uses less digits than its factorization.

251603666066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98823209.

The product of its (nonzero) digits is 1399680, while the sum is 47.

The spelling of 251603666066 in words is "two hundred fifty-one billion, six hundred three million, six hundred sixty-six thousand, sixty-six".