1666849977 has 12 divisors (see below), whose sum is σ = 2592877924. Its totient is φ = 1025753760.

The previous prime is 1666849973. The next prime is 1666849999. The reversal of 1666849977 is 7799486661.

It can be written as a sum of positive squares in 2 ways, for example, as 261274896 + 1405575081 = 16164^2 + 37491^2 .

It is not a de Polignac number, because 1666849977 - 2² = 1666849973 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666849973) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7123174 + ... + 7123407.

Almost surely, 2^1666849977 is an apocalyptic number.

It is an amenable number.

1666849977 is a deficient number, since it is larger than the sum of its proper divisors (926027947).

1666849977 is a wasteful number, since it uses less digits than its factorization.

1666849977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14246600 (or 14246597 counting only the distinct ones).

The product of its digits is 27433728, while the sum is 63.

The square root of 1666849977 is about 40827.0740685639. The cubic root of 1666849977 is about 1185.6745675897.

The spelling of 1666849977 in words is "one billion, six hundred sixty-six million, eight hundred forty-nine thousand, nine hundred seventy-seven".