19639990 has 8 divisors (see below), whose sum is σ = 35352000. Its totient is φ = 7855992.

The previous prime is 19639967. The next prime is 19640003. The reversal of 19639990 is 9993691.

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

It is a self number, because there is not a number n which added to its sum of digits gives 19639990.

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, 981990 + ... + 982009.

It is an arithmetic number, because the mean of its divisors is an integer number (4419000).

Almost surely, 2^19639990 is an apocalyptic number.

19639990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19639990 is a deficient number, since it is larger than the sum of its proper divisors (15712010).

19639990 is a wasteful number, since it uses less digits than its factorization.

19639990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1964006.

The product of its (nonzero) digits is 118098, while the sum is 46.

The square root of 19639990 is about 4431.7028329977. The cubic root of 19639990 is about 269.8031944873.

It can be divided in two parts, 196 and 39990, that added together give a triangular number (40186 = T₂₈₃).

The spelling of 19639990 in words is "nineteen million, six hundred thirty-nine thousand, nine hundred ninety".