66977923 has 2 divisors, whose sum is σ = 66977924. Its totient is φ = 66977922.

The previous prime is 66977899. The next prime is 66977951. The reversal of 66977923 is 32977966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66977923 - 2⁹ = 66977411 is a prime.

It is not a weakly prime, because it can be changed into another prime (66977023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33488961 + 33488962.

It is an arithmetic number, because the mean of its divisors is an integer number (33488962).

Almost surely, 2^66977923 is an apocalyptic number.

66977923 is a deficient number, since it is larger than the sum of its proper divisors (1).

66977923 is an equidigital number, since it uses as much as digits as its factorization.

66977923 is an evil number, because the sum of its binary digits is even.

The product of its digits is 857304, while the sum is 49.

The square root of 66977923 is about 8184.0040933519. The cubic root of 66977923 is about 406.1101947969.

The spelling of 66977923 in words is "sixty-six million, nine hundred seventy-seven thousand, nine hundred twenty-three".