21802842 has 48 divisors (see below), whose sum is σ = 51099360. Its totient is φ = 6695136.

The previous prime is 21802819. The next prime is 21802871. The reversal of 21802842 is 24820812.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11793 + ... + 13515.

It is an arithmetic number, because the mean of its divisors is an integer number (1064570).

Almost surely, 2^21802842 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21802842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25549680).

21802842 is an abundant number, since it is smaller than the sum of its proper divisors (29296518).

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

21802842 is a wasteful number, since it uses less digits than its factorization.

21802842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1787 (or 1784 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 21802842 is about 4669.3513468147. The cubic root of 21802842 is about 279.3643830327.

The spelling of 21802842 in words is "twenty-one million, eight hundred two thousand, eight hundred forty-two".