66681340074 has 16 divisors (see below), whose sum is σ = 148180755840. Its totient is φ = 22227113340.

The previous prime is 66681340021. The next prime is 66681340079. The reversal of 66681340074 is 47004318666.

It is a happy number.

It is a super-2 number, since 2×66681340074² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (66681340079) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 617419762 + ... + 617419869.

It is an arithmetic number, because the mean of its divisors is an integer number (9261297240).

Almost surely, 2^66681340074 is an apocalyptic number.

66681340074 is an abundant number, since it is smaller than the sum of its proper divisors (81499415766).

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

66681340074 is a wasteful number, since it uses less digits than its factorization.

66681340074 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1234839642 (or 1234839636 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The spelling of 66681340074 in words is "sixty-six billion, six hundred eighty-one million, three hundred forty thousand, seventy-four".