21984738 has 16 divisors (see below), whose sum is σ = 44032896. Its totient is φ = 7317680.

The previous prime is 21984737. The next prime is 21984749. The reversal of 21984738 is 83748912.

It is a self number, because there is not a number n which added to its sum of digits gives 21984738.

It is not an unprimeable number, because it can be changed into a prime (21984737) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2695 + ... + 7157.

It is an arithmetic number, because the mean of its divisors is an integer number (2752056).

Almost surely, 2^21984738 is an apocalyptic number.

21984738 is an abundant number, since it is smaller than the sum of its proper divisors (22048158).

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

21984738 is a wasteful number, since it uses less digits than its factorization.

21984738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5289.

The product of its digits is 96768, while the sum is 42.

The square root of 21984738 is about 4688.7885428968. The cubic root of 21984738 is about 280.1391230396.

It can be divided in two parts, 21984 and 738, that added together give a palindrome (22722).

The spelling of 21984738 in words is "twenty-one million, nine hundred eighty-four thousand, seven hundred thirty-eight".