21963916 has 18 divisors (see below), whose sum is σ = 41622252. Its totient is φ = 10136880.

The previous prime is 21963883. The next prime is 21963917. The reversal of 21963916 is 61936912.

It is not an unprimeable number, because it can be changed into a prime (21963917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 15570 + ... + 16921.

Almost surely, 2^21963916 is an apocalyptic number.

21963916 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21963916 is a deficient number, since it is larger than the sum of its proper divisors (19658336).

21963916 is a wasteful number, since it uses less digits than its factorization.

21963916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32521 (or 32506 counting only the distinct ones).

The product of its digits is 17496, while the sum is 37.

The square root of 21963916 is about 4686.5676139367. The cubic root of 21963916 is about 280.0506541010.

The spelling of 21963916 in words is "twenty-one million, nine hundred sixty-three thousand, nine hundred sixteen".