21351211215312 has 160 divisors (see below), whose sum is σ = 61847403120000. Its totient is φ = 6290150031360.

The previous prime is 21351211215253. The next prime is 21351211215391.

21351211215312 is nontrivially palindromic in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 21351211215312.

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, 23962948 + ... + 24837980.

It is an arithmetic number, because the mean of its divisors is an integer number (386546269500).

Almost surely, 2^{21351211215312} is an apocalyptic number.

21351211215312 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21351211215312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30923701560000).

21351211215312 is an abundant number, since it is smaller than the sum of its proper divisors (40496191904688).

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

21351211215312 is a wasteful number, since it uses less digits than its factorization.

21351211215312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 876341 (or 876335 counting only the distinct ones).

The product of its digits is 3600, while the sum is 30.

The spelling of 21351211215312 in words is "twenty-one trillion, three hundred fifty-one billion, two hundred eleven million, two hundred fifteen thousand, three hundred twelve".