21363738 has 32 divisors (see below), whose sum is σ = 47148480. Its totient is φ = 6399360.

The previous prime is 21363703. The next prime is 21363739. The reversal of 21363738 is 83736312.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 21363699 and 21363708.

It is not an unprimeable number, because it can be changed into a prime (21363739) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 4056 + ... + 7692.

It is an arithmetic number, because the mean of its divisors is an integer number (1473390).

Almost surely, 2^21363738 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21363738, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23574240).

21363738 is an abundant number, since it is smaller than the sum of its proper divisors (25784742).

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

21363738 is a wasteful number, since it uses less digits than its factorization.

21363738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3742.

The product of its digits is 18144, while the sum is 33.

The square root of 21363738 is about 4622.0923833260. The cubic root of 21363738 is about 277.4762060599.

The spelling of 21363738 in words is "twenty-one million, three hundred sixty-three thousand, seven hundred thirty-eight".