21768822 has 12 divisors (see below), whose sum is σ = 47165820. Its totient is φ = 7256268.

The previous prime is 21768811. The next prime is 21768847. The reversal of 21768822 is 22886712.

It is a happy number.

It is a super-3 number, since 3×21768822³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 604672 + ... + 604707.

It is an arithmetic number, because the mean of its divisors is an integer number (3930485).

Almost surely, 2^21768822 is an apocalyptic number.

21768822 is an abundant number, since it is smaller than the sum of its proper divisors (25396998).

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

21768822 is a wasteful number, since it uses less digits than its factorization.

21768822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1209387 (or 1209384 counting only the distinct ones).

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

The square root of 21768822 is about 4665.7070203775. The cubic root of 21768822 is about 279.2190055973.

The spelling of 21768822 in words is "twenty-one million, seven hundred sixty-eight thousand, eight hundred twenty-two".