19798990 has 8 divisors (see below), whose sum is σ = 35638200. Its totient is φ = 7919592.

The previous prime is 19798981. The next prime is 19798991. The reversal of 19798990 is 9989791.

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 (19798991) 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, 989940 + ... + 989959.

It is an arithmetic number, because the mean of its divisors is an integer number (4454775).

Almost surely, 2^19798990 is an apocalyptic number.

19798990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19798990 is a deficient number, since it is larger than the sum of its proper divisors (15839210).

19798990 is a wasteful number, since it uses less digits than its factorization.

19798990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1979906.

The product of its (nonzero) digits is 367416, while the sum is 52.

The square root of 19798990 is about 4449.6056004999. The cubic root of 19798990 is about 270.5293228337.

The spelling of 19798990 in words is "nineteen million, seven hundred ninety-eight thousand, nine hundred ninety".