18193977 has 10 divisors (see below), whose sum is σ = 27178778. Its totient is φ = 12129264.

The previous prime is 18193969. The next prime is 18194021. The reversal of 18193977 is 77939181.

It can be written as a sum of positive squares in only one way, i.e., 13682601 + 4511376 = 3699^2 + 2124^2 .

It is not a de Polignac number, because 18193977 - 2³ = 18193969 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18193957) by changing a digit.

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 in 9 ways as a sum of consecutive naturals, for example, 112228 + ... + 112389.

Almost surely, 2^18193977 is an apocalyptic number.

It is an amenable number.

18193977 is a deficient number, since it is larger than the sum of its proper divisors (8984801).

18193977 is an equidigital number, since it uses as much as digits as its factorization.

18193977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224629 (or 224620 counting only the distinct ones).

The product of its digits is 95256, while the sum is 45.

The square root of 18193977 is about 4265.4398366405. The cubic root of 18193977 is about 263.0121917946.

The spelling of 18193977 in words is "eighteen million, one hundred ninety-three thousand, nine hundred seventy-seven".