1666377764 has 6 divisors (see below), whose sum is σ = 2916161094. Its totient is φ = 833188880.

The previous prime is 1666377743. The next prime is 1666377773. The reversal of 1666377764 is 4677736661.

It can be written as a sum of positive squares in only one way, i.e., 1321904164 + 344473600 = 36358^2 + 18560^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 208297217 + ... + 208297224.

It is an arithmetic number, because the mean of its divisors is an integer number (486026849).

Almost surely, 2^1666377764 is an apocalyptic number.

It is an amenable number.

1666377764 is a deficient number, since it is larger than the sum of its proper divisors (1249783330).

1666377764 is a wasteful number, since it uses less digits than its factorization.

1666377764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416594445 (or 416594443 counting only the distinct ones).

The product of its digits is 5334336, while the sum is 53.

The square root of 1666377764 is about 40821.2905724452. The cubic root of 1666377764 is about 1185.5625911406.

The spelling of 1666377764 in words is "one billion, six hundred sixty-six million, three hundred seventy-seven thousand, seven hundred sixty-four".