21562842 has 48 divisors (see below), whose sum is σ = 50922432. Its totient is φ = 6068160.

The previous prime is 21562837. The next prime is 21562847. The reversal of 21562842 is 24826512.

It is an interprime number because it is at equal distance from previous prime (21562837) and next prime (21562847).

It is not an unprimeable number, because it can be changed into a prime (21562847) 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 23 ways as a sum of consecutive naturals, for example, 20358 + ... + 21390.

It is an arithmetic number, because the mean of its divisors is an integer number (1060884).

Almost surely, 2^21562842 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21562842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25461216).

21562842 is an abundant number, since it is smaller than the sum of its proper divisors (29359590).

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

21562842 is a wasteful number, since it uses less digits than its factorization.

21562842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1123 (or 1116 counting only the distinct ones).

The product of its digits is 7680, while the sum is 30.

The square root of 21562842 is about 4643.5807304278. The cubic root of 21562842 is about 278.3355419126.

The spelling of 21562842 in words is "twenty-one million, five hundred sixty-two thousand, eight hundred forty-two".