8190021 has 8 divisors (see below), whose sum is σ = 12480064. Its totient is φ = 4680000.

The previous prime is 8190011. The next prime is 8190029. The reversal of 8190021 is 1200918.

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

It is not a de Polignac number, because 8190021 - 2⁶ = 8189957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 390001 = 8190021 / (8 + 1 + 9 + 0 + 0 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 8190021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8190029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 194980 + ... + 195021.

It is an arithmetic number, because the mean of its divisors is an integer number (1560008).

Almost surely, 2^8190021 is an apocalyptic number.

It is an amenable number.

8190021 is a deficient number, since it is larger than the sum of its proper divisors (4290043).

8190021 is a wasteful number, since it uses less digits than its factorization.

8190021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390011.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 8190021 is about 2861.8212732454. The cubic root of 8190021 is about 201.5711337087.

Adding to 8190021 its reverse (1200918), we get a palindrome (9390939).

The spelling of 8190021 in words is "eight million, one hundred ninety thousand, twenty-one".