866549977 has 2 divisors, whose sum is σ = 866549978. Its totient is φ = 866549976.

The previous prime is 866549941. The next prime is 866550011. The reversal of 866549977 is 779945668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 559984896 + 306565081 = 23664^2 + 17509^2 .

It is a cyclic number.

It is not a de Polignac number, because 866549977 - 2¹⁹ = 866025689 is a prime.

It is not a weakly prime, because it can be changed into another prime (866549077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433274988 + 433274989.

It is an arithmetic number, because the mean of its divisors is an integer number (433274989).

Almost surely, 2^866549977 is an apocalyptic number.

It is an amenable number.

866549977 is a deficient number, since it is larger than the sum of its proper divisors (1).

866549977 is an equidigital number, since it uses as much as digits as its factorization.

866549977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22861440, while the sum is 61.

The square root of 866549977 is about 29437.2209455988. The cubic root of 866549977 is about 953.3767099954.

The spelling of 866549977 in words is "eight hundred sixty-six million, five hundred forty-nine thousand, nine hundred seventy-seven".