66994393854 has 32 divisors (see below), whose sum is σ = 134370694656. Its totient is φ = 22267889280.

The previous prime is 66994393831. The next prime is 66994393867. The reversal of 66994393854 is 45839349966.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3900774 + ... + 3917910.

It is an arithmetic number, because the mean of its divisors is an integer number (4199084208).

Almost surely, 2^66994393854 is an apocalyptic number.

66994393854 is an abundant number, since it is smaller than the sum of its proper divisors (67376300802).

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

66994393854 is a wasteful number, since it uses less digits than its factorization.

66994393854 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18960.

The product of its digits is 151165440, while the sum is 66.

The spelling of 66994393854 in words is "sixty-six billion, nine hundred ninety-four million, three hundred ninety-three thousand, eight hundred fifty-four".