199021021 has 8 divisors (see below), whose sum is σ = 203051264. Its totient is φ = 195022080.

The previous prime is 199021019. The next prime is 199021037. The reversal of 199021021 is 120120991.

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 199021021 - 2¹ = 199021019 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 (199021051) 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, 5236 + ... + 20626.

It is an arithmetic number, because the mean of its divisors is an integer number (25381408).

Almost surely, 2^199021021 is an apocalyptic number.

It is an amenable number.

199021021 is a deficient number, since it is larger than the sum of its proper divisors (4030243).

199021021 is a wasteful number, since it uses less digits than its factorization.

199021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15651.

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 199021021 is about 14107.4810295814. The cubic root of 199021021 is about 583.8478025310.

The spelling of 199021021 in words is "one hundred ninety-nine million, twenty-one thousand, twenty-one".