21422124 has 48 divisors (see below), whose sum is σ = 55977600. Its totient is φ = 7084368.

The previous prime is 21422119. The next prime is 21422129. The reversal of 21422124 is 42122412.

It is an interprime number because it is at equal distance from previous prime (21422119) and next prime (21422129).

It is a Harshad number since it is a multiple of its sum of digits (18).

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

It is a junction number, because it is equal to n+sod(n) for n = 21422097 and 21422106.

It is not an unprimeable number, because it can be changed into a prime (21422129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14299 + ... + 15725.

It is an arithmetic number, because the mean of its divisors is an integer number (1166200).

It is a self-describing number.

Almost surely, 2^21422124 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 21422124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27988800).

21422124 is an abundant number, since it is smaller than the sum of its proper divisors (34555476).

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

21422124 is a wasteful number, since it uses less digits than its factorization.

21422124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1579 (or 1571 counting only the distinct ones).

The product of its digits is 256, while the sum is 18.

The square root of 21422124 is about 4628.4040445925. The cubic root of 21422124 is about 277.7287522131.

Adding to 21422124 its reverse (42122412), we get a palindrome (63544536).

The spelling of 21422124 in words is "twenty-one million, four hundred twenty-two thousand, one hundred twenty-four".