18643977 has 12 divisors (see below), whose sum is σ = 29378544. Its totient is φ = 11299320.

The previous prime is 18643949. The next prime is 18643991. The reversal of 18643977 is 77934681.

It is not a de Polignac number, because 18643977 - 2¹⁴ = 18627593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18643477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 94063 + ... + 94260.

It is an arithmetic number, because the mean of its divisors is an integer number (2448212).

Almost surely, 2^18643977 is an apocalyptic number.

It is an amenable number.

18643977 is a deficient number, since it is larger than the sum of its proper divisors (10734567).

18643977 is a wasteful number, since it uses less digits than its factorization.

18643977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188340 (or 188337 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The square root of 18643977 is about 4317.8671818387. The cubic root of 18643977 is about 265.1629566136.

The spelling of 18643977 in words is "eighteen million, six hundred forty-three thousand, nine hundred seventy-seven".