21005022 has 16 divisors (see below), whose sum is σ = 42063120. Its totient is φ = 6992832.

The previous prime is 21005009. The next prime is 21005029. The reversal of 21005022 is 22050012.

It is a junction number, because it is equal to n+sod(n) for n = 21004989 and 21005007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21005029) 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, 4504 + ... + 7892.

It is an arithmetic number, because the mean of its divisors is an integer number (2628945).

Almost surely, 2^21005022 is an apocalyptic number.

21005022 is an abundant number, since it is smaller than the sum of its proper divisors (21058098).

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

21005022 is a wasteful number, since it uses less digits than its factorization.

21005022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4427.

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 21005022 is about 4583.1236073228. The cubic root of 21005022 is about 275.9144084522.

Adding to 21005022 its reverse (22050012), we get a palindrome (43055034).

The spelling of 21005022 in words is "twenty-one million, five thousand, twenty-two".