66979873 has 2 divisors, whose sum is σ = 66979874. Its totient is φ = 66979872.

The previous prime is 66979823. The next prime is 66979877. The reversal of 66979873 is 37897966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43718544 + 23261329 = 6612^2 + 4823^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66979873 is a prime.

It is a super-2 number, since 2×66979873² = 8972606774192258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66979877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33489936 + 33489937.

It is an arithmetic number, because the mean of its divisors is an integer number (33489937).

Almost surely, 2^66979873 is an apocalyptic number.

It is an amenable number.

66979873 is a deficient number, since it is larger than the sum of its proper divisors (1).

66979873 is an equidigital number, since it uses as much as digits as its factorization.

66979873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3429216, while the sum is 55.

The square root of 66979873 is about 8184.1232273225. The cubic root of 66979873 is about 406.1141359323.

The spelling of 66979873 in words is "sixty-six million, nine hundred seventy-nine thousand, eight hundred seventy-three".