19990693 has 8 divisors (see below), whose sum is σ = 20596760. Its totient is φ = 19388160.

The previous prime is 19990687. The next prime is 19990697. The reversal of 19990693 is 39609991.

It can be written as a sum of positive squares in 4 ways, for example, as 16176484 + 3814209 = 4022^2 + 1953^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19990693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19990697) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14473 + ... + 15793.

It is an arithmetic number, because the mean of its divisors is an integer number (2574595).

Almost surely, 2^19990693 is an apocalyptic number.

It is an amenable number.

19990693 is a deficient number, since it is larger than the sum of its proper divisors (606067).

19990693 is a wasteful number, since it uses less digits than its factorization.

19990693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1767.

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

The square root of 19990693 is about 4471.0952796826. The cubic root of 19990693 is about 271.3996499853.

The spelling of 19990693 in words is "nineteen million, nine hundred ninety thousand, six hundred ninety-three".