19785990 has 32 divisors (see below), whose sum is σ = 54270720. Its totient is φ = 4522464.

The previous prime is 19785979. The next prime is 19786027. The reversal of 19785990 is 9958791.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46900 + ... + 47319.

It is an arithmetic number, because the mean of its divisors is an integer number (1695960).

Almost surely, 2^19785990 is an apocalyptic number.

19785990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19785990 is an abundant number, since it is smaller than the sum of its proper divisors (34484730).

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

19785990 is a wasteful number, since it uses less digits than its factorization.

19785990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94236.

The product of its (nonzero) digits is 204120, while the sum is 48.

The square root of 19785990 is about 4448.1445570035. The cubic root of 19785990 is about 270.4701000955.

The spelling of 19785990 in words is "nineteen million, seven hundred eighty-five thousand, nine hundred ninety".