21022002000 has 120 divisors (see below), whose sum is σ = 73422908520. Its totient is φ = 5605862400.

The previous prime is 21022001977. The next prime is 21022002011. The reversal of 21022002000 is 20022012.

It can be written as a sum of positive squares in 4 ways, for example, as 2784039696 + 18237962304 = 52764^2 + 135048^2 .

It is a tau number, because it is divible by the number of its divisors (120).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 565945 + ... + 601944.

It is an arithmetic number, because the mean of its divisors is an integer number (611857571).

Almost surely, 2^21022002000 is an apocalyptic number.

21022002000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21022002000 is an abundant number, since it is smaller than the sum of its proper divisors (52400906520).

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

21022002000 is a wasteful number, since it uses less digits than its factorization.

21022002000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1167918 (or 1167899 counting only the distinct ones).

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

Adding to 21022002000 its reverse (20022012), we get a palindrome (21042024012).

The spelling of 21022002000 in words is "twenty-one billion, twenty-two million, two thousand".