21002000022 has 72 divisors (see below), whose sum is σ = 48404295576. Its totient is φ = 6558461184.

The previous prime is 21002000021. The next prime is 21002000053. The reversal of 21002000022 is 22000020012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21001999968 and 21002000013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002000021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 30749293 + ... + 30749975.

It is an arithmetic number, because the mean of its divisors is an integer number (672281883).

Almost surely, 2^21002000022 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21002000022, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24202147788).

21002000022 is an abundant number, since it is smaller than the sum of its proper divisors (27402295554).

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

21002000022 is a wasteful number, since it uses less digits than its factorization.

21002000022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1342 (or 1022 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

Adding to 21002000022 its reverse (22000020012), we get a palindrome (43002020034).

The spelling of 21002000022 in words is "twenty-one billion, two million, twenty-two", and thus it is an aban number and an uban number.