66813722 has 16 divisors (see below), whose sum is σ = 101607912. Its totient is φ = 32947200.

The previous prime is 66813707. The next prime is 66813737. The reversal of 66813722 is 22731866.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66813707) and next prime (66813737).

It can be written as a sum of positive squares in 4 ways, for example, as 55517401 + 11296321 = 7451^2 + 3361^2 .

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 7 ways as a sum of consecutive naturals, for example, 70838 + ... + 71774.

Almost surely, 2^66813722 is an apocalyptic number.

66813722 is a deficient number, since it is larger than the sum of its proper divisors (34794190).

66813722 is a wasteful number, since it uses less digits than its factorization.

66813722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1393.

The product of its digits is 24192, while the sum is 35.

The square root of 66813722 is about 8173.9661119924. The cubic root of 66813722 is about 405.7780541716.

The spelling of 66813722 in words is "sixty-six million, eight hundred thirteen thousand, seven hundred twenty-two".