21422940 has 96 divisors (see below), whose sum is σ = 74801664. Its totient is φ = 4450560.

The previous prime is 21422939. The next prime is 21422993. The reversal of 21422940 is 4922412.

It is a super-3 number, since 3×21422940³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21422940.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 2302 + ... + 6938.

It is an arithmetic number, because the mean of its divisors is an integer number (779184).

Almost surely, 2^21422940 is an apocalyptic number.

21422940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21422940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37400832).

21422940 is an abundant number, since it is smaller than the sum of its proper divisors (53378724).

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

21422940 is a wasteful number, since it uses less digits than its factorization.

21422940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4667 (or 4665 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 21422940 is about 4628.4921950890. The cubic root of 21422940 is about 277.7322785329.

The spelling of 21422940 in words is "twenty-one million, four hundred twenty-two thousand, nine hundred forty".