21202121310 has 64 divisors (see below), whose sum is σ = 52319361024. Its totient is φ = 5495558400.

The previous prime is 21202121273. The next prime is 21202121329. The reversal of 21202121310 is 1312120212.

It is a super-2 number, since 2×21202121310² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21202121310.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 301527 + ... + 365133.

It is an arithmetic number, because the mean of its divisors is an integer number (817490016).

Almost surely, 2^21202121310 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21202121310, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26159680512).

21202121310 is an abundant number, since it is smaller than the sum of its proper divisors (31117239714).

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

21202121310 is a wasteful number, since it uses less digits than its factorization.

21202121310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63929.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21202121310 its reverse (1312120212), we get a palindrome (22514241522).

The spelling of 21202121310 in words is "twenty-one billion, two hundred two million, one hundred twenty-one thousand, three hundred ten".