18157990 has 8 divisors (see below), whose sum is σ = 32684400. Its totient is φ = 7263192.

The previous prime is 18157961. The next prime is 18157991. The reversal of 18157990 is 9975181.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18157991) 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, 907890 + ... + 907909.

It is an arithmetic number, because the mean of its divisors is an integer number (4085550).

Almost surely, 2^18157990 is an apocalyptic number.

18157990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18157990 is a deficient number, since it is larger than the sum of its proper divisors (14526410).

18157990 is a wasteful number, since it uses less digits than its factorization.

18157990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1815806.

The product of its (nonzero) digits is 22680, while the sum is 40.

The square root of 18157990 is about 4261.2193090711. The cubic root of 18157990 is about 262.8386679393.

The spelling of 18157990 in words is "eighteen million, one hundred fifty-seven thousand, nine hundred ninety".