21874242 has 64 divisors (see below), whose sum is σ = 50077440. Its totient is φ = 6319104.

The previous prime is 21874241. The next prime is 21874261. The reversal of 21874242 is 24247812.

It is not an unprimeable number, because it can be changed into a prime (21874241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159598 + ... + 159734.

It is an arithmetic number, because the mean of its divisors is an integer number (782460).

Almost surely, 2^21874242 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21874242, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25038720).

21874242 is an abundant number, since it is smaller than the sum of its proper divisors (28203198).

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

21874242 is a wasteful number, since it uses less digits than its factorization.

21874242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267.

The product of its digits is 7168, while the sum is 30.

The square root of 21874242 is about 4676.9906991569. The cubic root of 21874242 is about 279.6690051355.

The spelling of 21874242 in words is "twenty-one million, eight hundred seventy-four thousand, two hundred forty-two".