21862368 has 144 divisors (see below), whose sum is σ = 69503616. Its totient is φ = 6462720.

The previous prime is 21862363. The next prime is 21862387. The reversal of 21862368 is 86326812.

21862368 is a `hidden beast` number, since 21 + 8 + 623 + 6 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21862363) 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 23 ways as a sum of consecutive naturals, for example, 212205 + ... + 212307.

It is an arithmetic number, because the mean of its divisors is an integer number (482664).

Almost surely, 2^21862368 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21862368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34751808).

21862368 is an abundant number, since it is smaller than the sum of its proper divisors (47641248).

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

21862368 is a wasteful number, since it uses less digits than its factorization.

21862368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197 (or 186 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 21862368 is about 4675.7211208540. The cubic root of 21862368 is about 279.6183917120.

It can be divided in two parts, 2186 and 2368, that added together give a palindrome (4554).

The spelling of 21862368 in words is "twenty-one million, eight hundred sixty-two thousand, three hundred sixty-eight".