66886979 has 2 divisors, whose sum is σ = 66886980. Its totient is φ = 66886978.

The previous prime is 66886909. The next prime is 66886987. The reversal of 66886979 is 97968866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66886979 - 2⁸ = 66886723 is a prime.

It is not a weakly prime, because it can be changed into another prime (66886909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33443489 + 33443490.

It is an arithmetic number, because the mean of its divisors is an integer number (33443490).

Almost surely, 2^66886979 is an apocalyptic number.

66886979 is a deficient number, since it is larger than the sum of its proper divisors (1).

66886979 is an equidigital number, since it uses as much as digits as its factorization.

66886979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7838208, while the sum is 59.

The square root of 66886979 is about 8178.4460015335. The cubic root of 66886979 is about 405.9263032857.

The spelling of 66886979 in words is "sixty-six million, eight hundred eighty-six thousand, nine hundred seventy-nine".