66981457125854 has 32 divisors (see below), whose sum is σ = 101062856217600. Its totient is φ = 33294329339040.

The previous prime is 66981457125809. The next prime is 66981457125871. The reversal of 66981457125854 is 45852175418966.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2236651709 + ... + 2236681655.

It is an arithmetic number, because the mean of its divisors is an integer number (3158214256800).

Almost surely, 2^{66981457125854} is an apocalyptic number.

66981457125854 is a deficient number, since it is larger than the sum of its proper divisors (34081399091746).

66981457125854 is a wasteful number, since it uses less digits than its factorization.

66981457125854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37928.

The product of its digits is 580608000, while the sum is 71.

The spelling of 66981457125854 in words is "sixty-six trillion, nine hundred eighty-one billion, four hundred fifty-seven million, one hundred twenty-five thousand, eight hundred fifty-four".