18990798 has 8 divisors (see below), whose sum is σ = 37981608. Its totient is φ = 6330264.

The previous prime is 18990793. The next prime is 18990809. The reversal of 18990798 is 89709981.

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

18990798 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 18990798.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18990793) 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, 1582561 + ... + 1582572.

It is an arithmetic number, because the mean of its divisors is an integer number (4747701).

Almost surely, 2^18990798 is an apocalyptic number.

18990798 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18990798 is a wasteful number, since it uses less digits than its factorization.

18990798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3165138.

The product of its (nonzero) digits is 326592, while the sum is 51.

The square root of 18990798 is about 4357.8432739143. The cubic root of 18990798 is about 266.7970796141.

The spelling of 18990798 in words is "eighteen million, nine hundred ninety thousand, seven hundred ninety-eight".