21924942 has 64 divisors (see below), whose sum is σ = 49641984. Its totient is φ = 6410880.

The previous prime is 21924941. The next prime is 21924943. The reversal of 21924942 is 24942912.

It is an interprime number because it is at equal distance from previous prime (21924941) and next prime (21924943).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21924941) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 204853 + ... + 204959.

It is an arithmetic number, because the mean of its divisors is an integer number (775656).

Almost surely, 2^21924942 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21924942, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24820992).

21924942 is an abundant number, since it is smaller than the sum of its proper divisors (27717042).

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

21924942 is a wasteful number, since it uses less digits than its factorization.

21924942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233.

The product of its digits is 10368, while the sum is 33.

The square root of 21924942 is about 4682.4077139865. The cubic root of 21924942 is about 279.8849101835.

The spelling of 21924942 in words is "twenty-one million, nine hundred twenty-four thousand, nine hundred forty-two".