20821190 has 16 divisors (see below), whose sum is σ = 40361328. Its totient is φ = 7687776.

The previous prime is 20821117. The next prime is 20821193. The reversal of 20821190 is 9112802.

It is a super-2 number, since 2×20821190² = 867043906032200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20821193) 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, 79952 + ... + 80211.

It is an arithmetic number, because the mean of its divisors is an integer number (2522583).

Almost surely, 2^20821190 is an apocalyptic number.

20821190 is a deficient number, since it is larger than the sum of its proper divisors (19540138).

20821190 is a wasteful number, since it uses less digits than its factorization.

20821190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160183.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 20821190 is about 4563.0242164600. The cubic root of 20821190 is about 275.1071318129.

Adding to 20821190 its reverse (9112802), we get a palindrome (29933992).

The spelling of 20821190 in words is "twenty million, eight hundred twenty-one thousand, one hundred ninety".