18923990 has 8 divisors (see below), whose sum is σ = 34063200. Its totient is φ = 7569592.

The previous prime is 18923987. The next prime is 18924011. The reversal of 18923990 is 9932981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 946190 + ... + 946209.

It is an arithmetic number, because the mean of its divisors is an integer number (4257900).

Almost surely, 2^18923990 is an apocalyptic number.

18923990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18923990 is a deficient number, since it is larger than the sum of its proper divisors (15139210).

18923990 is a wasteful number, since it uses less digits than its factorization.

18923990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1892406.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 18923990 is about 4350.1712609965. The cubic root of 18923990 is about 266.4838556069.

The spelling of 18923990 in words is "eighteen million, nine hundred twenty-three thousand, nine hundred ninety".