21021200010 has 48 divisors (see below), whose sum is σ = 55313635104. Its totient is φ = 5538113376.

The previous prime is 21021199973. The next prime is 21021200023. The reversal of 21021200010 is 1000212012.

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 = 21021199965 and 21021200001.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 1399572 + ... + 1414511.

It is an arithmetic number, because the mean of its divisors is an integer number (1152367398).

Almost surely, 2^21021200010 is an apocalyptic number.

21021200010 is an abundant number, since it is smaller than the sum of its proper divisors (34292435094).

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

21021200010 is a wasteful number, since it uses less digits than its factorization.

21021200010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2814179 (or 2814176 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21021200010 its reverse (1000212012), we get a palindrome (22021412022).

The spelling of 21021200010 in words is "twenty-one billion, twenty-one million, two hundred thousand, ten".