666077977 has 4 divisors (see below), whose sum is σ = 678645540. Its totient is φ = 653510416.

The previous prime is 666077939. The next prime is 666077983. The reversal of 666077977 is 779770666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 779770666 = 2 ⋅389885333.

It can be written as a sum of positive squares in 2 ways, for example, as 613602441 + 52475536 = 24771^2 + 7244^2 .

It is a cyclic number.

It is not a de Polignac number, because 666077977 - 2²³ = 657689369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666077987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6283702 + ... + 6283807.

It is an arithmetic number, because the mean of its divisors is an integer number (169661385).

Almost surely, 2^666077977 is an apocalyptic number.

It is an amenable number.

666077977 is a deficient number, since it is larger than the sum of its proper divisors (12567563).

666077977 is a wasteful number, since it uses less digits than its factorization.

666077977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12567562.

The product of its (nonzero) digits is 4667544, while the sum is 55.

The square root of 666077977 is about 25808.4865305969. The cubic root of 666077977 is about 873.3232551168.

The spelling of 666077977 in words is "six hundred sixty-six million, seventy-seven thousand, nine hundred seventy-seven".