18123977 has 4 divisors (see below), whose sum is σ = 18912000. Its totient is φ = 17335956.

The previous prime is 18123953. The next prime is 18123979. The reversal of 18123977 is 77932181.

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, and also an emirpimes, since its reverse is a distinct semiprime: 77932181 = 199 ⋅391619.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18123977 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18123977.

It is not an unprimeable number, because it can be changed into a prime (18123979) 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, 393977 + ... + 394022.

It is an arithmetic number, because the mean of its divisors is an integer number (4728000).

Almost surely, 2^18123977 is an apocalyptic number.

It is an amenable number.

18123977 is a deficient number, since it is larger than the sum of its proper divisors (788023).

18123977 is an equidigital number, since it uses as much as digits as its factorization.

18123977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 788022.

The product of its digits is 21168, while the sum is 38.

The square root of 18123977 is about 4257.2264445293. The cubic root of 18123977 is about 262.6744515359.

The spelling of 18123977 in words is "eighteen million, one hundred twenty-three thousand, nine hundred seventy-seven".