18723797 has 4 divisors (see below), whose sum is σ = 19709280. Its totient is φ = 17738316.

The previous prime is 18723781. The next prime is 18723829. The reversal of 18723797 is 79732781.

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: 79732781 = 2909 ⋅27409.

It is a cyclic number.

It is not a de Polignac number, because 18723797 - 2⁴ = 18723781 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 (18723997) 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, 492713 + ... + 492750.

It is an arithmetic number, because the mean of its divisors is an integer number (4927320).

Almost surely, 2^18723797 is an apocalyptic number.

It is an amenable number.

18723797 is a deficient number, since it is larger than the sum of its proper divisors (985483).

18723797 is an equidigital number, since it uses as much as digits as its factorization.

18723797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985482.

The product of its digits is 148176, while the sum is 44.

The square root of 18723797 is about 4327.1002992766. The cubic root of 18723797 is about 265.5408297465.

The spelling of 18723797 in words is "eighteen million, seven hundred twenty-three thousand, seven hundred ninety-seven".