199920621 has 8 divisors (see below), whose sum is σ = 266631264. Its totient is φ = 133245200.

The previous prime is 199920547. The next prime is 199920649. The reversal of 199920621 is 126029991.

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

It is a cyclic number.

It is not a de Polignac number, because 199920621 - 2¹¹ = 199918573 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199920621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199920121) 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, 10471 + ... + 22571.

It is an arithmetic number, because the mean of its divisors is an integer number (33328908).

Almost surely, 2^199920621 is an apocalyptic number.

It is an amenable number.

199920621 is a deficient number, since it is larger than the sum of its proper divisors (66710643).

199920621 is a wasteful number, since it uses less digits than its factorization.

199920621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17611.

The product of its (nonzero) digits is 17496, while the sum is 39.

The square root of 199920621 is about 14139.3288737479. The cubic root of 199920621 is about 584.7261688699.

The spelling of 199920621 in words is "one hundred ninety-nine million, nine hundred twenty thousand, six hundred twenty-one".