66711721582 has 48 divisors (see below), whose sum is σ = 114874806816. Its totient is φ = 28979596800.

The previous prime is 66711721561. The next prime is 66711721603. The reversal of 66711721582 is 28512711766.

It is an interprime number because it is at equal distance from previous prime (66711721561) and next prime (66711721603).

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7214482 + ... + 7223722.

It is an arithmetic number, because the mean of its divisors is an integer number (2393225142).

Almost surely, 2^66711721582 is an apocalyptic number.

66711721582 is a deficient number, since it is larger than the sum of its proper divisors (48163085234).

66711721582 is a wasteful number, since it uses less digits than its factorization.

66711721582 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10585 (or 10574 counting only the distinct ones).

The product of its digits is 282240, while the sum is 46.

The spelling of 66711721582 in words is "sixty-six billion, seven hundred eleven million, seven hundred twenty-one thousand, five hundred eighty-two".