21000012120321 has 32 divisors (see below), whose sum is σ = 30686714352000. Its totient is φ = 12695030734848.

The previous prime is 21000012120317. The next prime is 21000012120413. The reversal of 21000012120321 is 12302121000012.

It is not a de Polignac number, because 21000012120321 - 2² = 21000012120317 is a prime.

It is a super-2 number, since 2×21000012120321² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21000012120321.

It is not an unprimeable number, because it can be changed into a prime (21000012120721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3475 + ... + 6480743.

It is an arithmetic number, because the mean of its divisors is an integer number (958959823500).

Almost surely, 2^{21000012120321} is an apocalyptic number.

It is an amenable number.

21000012120321 is a deficient number, since it is larger than the sum of its proper divisors (9686702231679).

21000012120321 is a wasteful number, since it uses less digits than its factorization.

21000012120321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6478753.

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

Adding to 21000012120321 its reverse (12302121000012), we get a palindrome (33302133120333).

The spelling of 21000012120321 in words is "twenty-one trillion, twelve million, one hundred twenty thousand, three hundred twenty-one".