21886722 has 72 divisors (see below), whose sum is σ = 56206332. Its totient is φ = 6114240.

The previous prime is 21886703. The next prime is 21886729. The reversal of 21886722 is 22768812.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17564481 + 4322241 = 4191^2 + 2079^2 .

It is not an unprimeable number, because it can be changed into a prime (21886729) 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 35 ways as a sum of consecutive naturals, for example, 27928 + ... + 28700.

Almost surely, 2^21886722 is an apocalyptic number.

21886722 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21886722, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28103166).

21886722 is an abundant number, since it is smaller than the sum of its proper divisors (34319610).

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

21886722 is a wasteful number, since it uses less digits than its factorization.

21886722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 816 (or 802 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 21886722 is about 4678.3247001464. The cubic root of 21886722 is about 279.7221819210.

The spelling of 21886722 in words is "twenty-one million, eight hundred eighty-six thousand, seven hundred twenty-two".