21021221302110 has 128 divisors (see below), whose sum is σ = 58538747381760. Its totient is φ = 5357817577728.

The previous prime is 21021221302099. The next prime is 21021221302121. The reversal of 21021221302110 is 1120312212012.

21021221302110 is a `hidden beast` number, since 2 + 10 + 21 + 221 + 302 + 110 = 666.

It is an interprime number because it is at equal distance from previous prime (21021221302099) and next prime (21021221302121).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6792682 + ... + 9390578.

It is an arithmetic number, because the mean of its divisors is an integer number (457333963920).

Almost surely, 2^{21021221302110} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21021221302110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29269373690880).

21021221302110 is an abundant number, since it is smaller than the sum of its proper divisors (37517526079650).

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

21021221302110 is a wasteful number, since it uses less digits than its factorization.

21021221302110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2599239 (or 2599233 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21021221302110 its reverse (1120312212012), we get a palindrome (22141533514122).

The spelling of 21021221302110 in words is "twenty-one trillion, twenty-one billion, two hundred twenty-one million, three hundred two thousand, one hundred ten".