21130121310 has 64 divisors (see below), whose sum is σ = 52548756480. Its totient is φ = 5433966720.

The previous prime is 21130121281. The next prime is 21130121359. The reversal of 21130121310 is 1312103112.

It is a happy number.

It is a super-2 number, since 2×21130121310² (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 21130121310.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 1761 + ... + 205580.

It is an arithmetic number, because the mean of its divisors is an integer number (821074320).

Almost surely, 2^21130121310 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21130121310, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26274378240).

21130121310 is an abundant number, since it is smaller than the sum of its proper divisors (31418635170).

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

21130121310 is a wasteful number, since it uses less digits than its factorization.

21130121310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207473.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21130121310 its reverse (1312103112), we get a palindrome (22442224422).

The spelling of 21130121310 in words is "twenty-one billion, one hundred thirty million, one hundred twenty-one thousand, three hundred ten".