21917016 has 48 divisors (see below), whose sum is σ = 64757160. Its totient is φ = 6641280.

The previous prime is 21917003. The next prime is 21917023. The reversal of 21917016 is 61071912.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 13045 + ... + 14628.

Almost surely, 2^21917016 is an apocalyptic number.

It is an amenable number.

21917016 is an abundant number, since it is smaller than the sum of its proper divisors (42840144).

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

21917016 is a wasteful number, since it uses less digits than its factorization.

21917016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27696 (or 27689 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 27.

The square root of 21917016 is about 4681.5612780354. The cubic root of 21917016 is about 279.8511794190.

Adding to 21917016 its reverse (61071912), we get a palindrome (82988928).

The spelling of 21917016 in words is "twenty-one million, nine hundred seventeen thousand, sixteen".