21940016 has 20 divisors (see below), whose sum is σ = 48581712. Its totient is φ = 9402816.

The previous prime is 21939997. The next prime is 21940027. The reversal of 21940016 is 61004912.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21939973 and 21940000.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97835 + ... + 98058.

Almost surely, 2^21940016 is an apocalyptic number.

It is an amenable number.

21940016 is an abundant number, since it is smaller than the sum of its proper divisors (26641696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21940016 is a wasteful number, since it uses less digits than its factorization.

21940016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195908 (or 195902 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21940016 is about 4684.0170793882. The cubic root of 21940016 is about 279.9490383443.

Adding to 21940016 its reverse (61004912), we get a palindrome (82944928).

The spelling of 21940016 in words is "twenty-one million, nine hundred forty thousand, sixteen".