16190021 has 4 divisors (see below), whose sum is σ = 16198092. Its totient is φ = 16181952.

The previous prime is 16190011. The next prime is 16190077. The reversal of 16190021 is 12009161.

16190021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12009161 = 29 ⋅414109.

It can be written as a sum of positive squares in 2 ways, for example, as 3330625 + 12859396 = 1825^2 + 3586^2 .

It is a cyclic number.

It is not a de Polignac number, because 16190021 - 2²² = 11995717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16189975 and 16190002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16190011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1565 + ... + 5901.

It is an arithmetic number, because the mean of its divisors is an integer number (4049523).

Almost surely, 2^16190021 is an apocalyptic number.

It is an amenable number.

16190021 is a deficient number, since it is larger than the sum of its proper divisors (8071).

16190021 is an equidigital number, since it uses as much as digits as its factorization.

16190021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8070.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 16190021 is about 4023.6825172968. The cubic root of 16190021 is about 252.9778345082.

Adding to 16190021 its reverse (12009161), we get a palindrome (28199182).

The spelling of 16190021 in words is "sixteen million, one hundred ninety thousand, twenty-one".