21000121331310 has 256 divisors, whose sum is σ = 61907778662400. Its totient is φ = 5023283558400.

The previous prime is 21000121331263. The next prime is 21000121331333. The reversal of 21000121331310 is 1313312100012.

21000121331310 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 0 + 1 + 21 + 331 + 310 = 666.

It is a super-2 number, since 2×21000121331310² (a number of 27 digits) contains 22 as substring.

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 127 ways as a sum of consecutive naturals, for example, 77884347 + ... + 78153513.

It is an arithmetic number, because the mean of its divisors is an integer number (241827260400).

Almost surely, 2^{21000121331310} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21000121331310, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30953889331200).

21000121331310 is an abundant number, since it is smaller than the sum of its proper divisors (40907657331090).

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

21000121331310 is a wasteful number, since it uses less digits than its factorization.

21000121331310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269544 (or 269538 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21000121331310 its reverse (1313312100012), we get a palindrome (22313433431322).

The spelling of 21000121331310 in words is "twenty-one trillion, one hundred twenty-one million, three hundred thirty-one thousand, three hundred ten".