21638322 has 12 divisors (see below), whose sum is σ = 46883070. Its totient is φ = 7212768.

The previous prime is 21638317. The next prime is 21638327. The reversal of 21638322 is 22383612.

21638322 is a `hidden beast` number, since 2 + 1 + 638 + 3 + 22 = 666.

It is an interprime number because it is at equal distance from previous prime (21638317) and next prime (21638327).

It can be written as a sum of positive squares in only one way, i.e., 21427641 + 210681 = 4629^2 + 459^2 .

It is not an unprimeable number, because it can be changed into a prime (21638327) 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, 601047 + ... + 601082.

Almost surely, 2^21638322 is an apocalyptic number.

21638322 is an abundant number, since it is smaller than the sum of its proper divisors (25244748).

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

21638322 is a wasteful number, since it uses less digits than its factorization.

21638322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1202137 (or 1202134 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 21638322 is about 4651.7009792118. The cubic root of 21638322 is about 278.6599317553.

The spelling of 21638322 in words is "twenty-one million, six hundred thirty-eight thousand, three hundred twenty-two".