21942024 has 32 divisors (see below), whose sum is σ = 59075520. Its totient is φ = 6751296.

The previous prime is 21942007. The next prime is 21942029. The reversal of 21942024 is 42024912.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 21941985 and 21942003.

It is not an unprimeable number, because it can be changed into a prime (21942029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34852 + ... + 35475.

It is an arithmetic number, because the mean of its divisors is an integer number (1846110).

Almost surely, 2^21942024 is an apocalyptic number.

21942024 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21942024 is an abundant number, since it is smaller than the sum of its proper divisors (37133496).

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

21942024 is a wasteful number, since it uses less digits than its factorization.

21942024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70349 (or 70345 counting only the distinct ones).

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

The square root of 21942024 is about 4684.2314204147. The cubic root of 21942024 is about 279.9575786073.

Subtracting from 21942024 its sum of digits (24), we obtain a triangular number (21942000 = T₆₆₂₄).

Adding to 21942024 its reverse (42024912), we get a palindrome (63966936).

The spelling of 21942024 in words is "twenty-one million, nine hundred forty-two thousand, twenty-four".