21021020110 has 32 divisors (see below), whose sum is σ = 37972426752. Its totient is φ = 8378543520.

The previous prime is 21021020099. The next prime is 21021020117. The reversal of 21021020110 is 1102012012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021020117) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5693365 + ... + 5697055.

It is an arithmetic number, because the mean of its divisors is an integer number (1186638336).

Almost surely, 2^21021020110 is an apocalyptic number.

21021020110 is a deficient number, since it is larger than the sum of its proper divisors (16951406642).

21021020110 is a wasteful number, since it uses less digits than its factorization.

21021020110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5568.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21021020110 its reverse (1102012012), we get a palindrome (22123032122).

The spelling of 21021020110 in words is "twenty-one billion, twenty-one million, twenty thousand, one hundred ten".