66613721372 has 12 divisors (see below), whose sum is σ = 127171649976. Its totient is φ = 30278964240.

The previous prime is 66613721347. The next prime is 66613721389. The reversal of 66613721372 is 27312731666.

It is a Harshad number since it is a multiple of its sum of digits (44), and also a Moran number because the ratio is a prime number: 1513948213 = 66613721372 / (6 + 6 + 6 + 1 + 3 + 7 + 2 + 1 + 3 + 7 + 2).

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 756974063 + ... + 756974150.

It is an arithmetic number, because the mean of its divisors is an integer number (10597637498).

Almost surely, 2^66613721372 is an apocalyptic number.

It is an amenable number.

66613721372 is a deficient number, since it is larger than the sum of its proper divisors (60557928604).

66613721372 is a wasteful number, since it uses less digits than its factorization.

66613721372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1513948228 (or 1513948226 counting only the distinct ones).

The product of its digits is 381024, while the sum is 44.

The spelling of 66613721372 in words is "sixty-six billion, six hundred thirteen million, seven hundred twenty-one thousand, three hundred seventy-two".