21230984 has 8 divisors (see below), whose sum is σ = 39808110. Its totient is φ = 10615488.

The previous prime is 21230969. The next prime is 21231029. The reversal of 21230984 is 48903212.

It can be written as a sum of positive squares in only one way, i.e., 16728100 + 4502884 = 4090^2 + 2122^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1326929 + ... + 1326944.

Almost surely, 2^21230984 is an apocalyptic number.

It is an amenable number.

21230984 is a deficient number, since it is larger than the sum of its proper divisors (18577126).

21230984 is a wasteful number, since it uses less digits than its factorization.

21230984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2653879 (or 2653875 counting only the distinct ones).

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

The square root of 21230984 is about 4607.7091922125. The cubic root of 21230984 is about 276.9002668930.

The spelling of 21230984 in words is "twenty-one million, two hundred thirty thousand, nine hundred eighty-four".