20721196 has 24 divisors (see below), whose sum is σ = 38041920. Its totient is φ = 9862272.

The previous prime is 20721163. The next prime is 20721209. The reversal of 20721196 is 69112702.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7245 + ... + 9691.

It is an arithmetic number, because the mean of its divisors is an integer number (1585080).

Almost surely, 2^20721196 is an apocalyptic number.

It is an amenable number.

20721196 is a deficient number, since it is larger than the sum of its proper divisors (17320724).

20721196 is a wasteful number, since it uses less digits than its factorization.

20721196 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2553 (or 2551 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 20721196 is about 4552.0540418585. The cubic root of 20721196 is about 274.6660232125. Note that the first 3 decimals are identical.

Adding to 20721196 its reverse (69112702), we get a palindrome (89833898).

The spelling of 20721196 in words is "twenty million, seven hundred twenty-one thousand, one hundred ninety-six".