66261977 has 2 divisors, whose sum is σ = 66261978. Its totient is φ = 66261976.

The previous prime is 66261953. The next prime is 66261991. The reversal of 66261977 is 77916266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44769481 + 21492496 = 6691^2 + 4636^2 .

It is a cyclic number.

It is not a de Polignac number, because 66261977 - 2⁶ = 66261913 is a prime.

It is not a weakly prime, because it can be changed into another prime (66261907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33130988 + 33130989.

It is an arithmetic number, because the mean of its divisors is an integer number (33130989).

Almost surely, 2^66261977 is an apocalyptic number.

It is an amenable number.

66261977 is a deficient number, since it is larger than the sum of its proper divisors (1).

66261977 is an equidigital number, since it uses as much as digits as its factorization.

66261977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 190512, while the sum is 44.

The square root of 66261977 is about 8140.1460060616. The cubic root of 66261977 is about 404.6579991425.

The spelling of 66261977 in words is "sixty-six million, two hundred sixty-one thousand, nine hundred seventy-seven".