664403777 has 4 divisors (see below), whose sum is σ = 667051056. Its totient is φ = 661756500.

The previous prime is 664403713. The next prime is 664403801. The reversal of 664403777 is 777304466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 664403777 - 2⁶ = 664403713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664403977) 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, 1323263 + ... + 1323764.

It is an arithmetic number, because the mean of its divisors is an integer number (166762764).

Almost surely, 2^664403777 is an apocalyptic number.

It is an amenable number.

664403777 is a deficient number, since it is larger than the sum of its proper divisors (2647279).

664403777 is a wasteful number, since it uses less digits than its factorization.

664403777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2647278.

The product of its (nonzero) digits is 592704, while the sum is 44.

The square root of 664403777 is about 25776.0310560024. The cubic root of 664403777 is about 872.5909361901.

The spelling of 664403777 in words is "six hundred sixty-four million, four hundred three thousand, seven hundred seventy-seven".