21320984 has 16 divisors (see below), whose sum is σ = 40952520. Its totient is φ = 10400320.

The previous prime is 21320969. The next prime is 21320987. The reversal of 21320984 is 48902312.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32174 + ... + 32829.

Almost surely, 2^21320984 is an apocalyptic number.

It is an amenable number.

21320984 is a deficient number, since it is larger than the sum of its proper divisors (19631536).

21320984 is a wasteful number, since it uses less digits than its factorization.

21320984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65050 (or 65046 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21320984 is about 4617.4651054448. The cubic root of 21320984 is about 277.2909834762.

The spelling of 21320984 in words is "twenty-one million, three hundred twenty thousand, nine hundred eighty-four".