21512534221311 has 24 divisors (see below), whose sum is σ = 33823453318704. Its totient is φ = 12124481120640.

The previous prime is 21512534221307. The next prime is 21512534221363. The reversal of 21512534221311 is 11312243521512.

It is not a de Polignac number, because 21512534221311 - 2² = 21512534221307 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21512534221301) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1002343860 + ... + 1002365321.

It is an arithmetic number, because the mean of its divisors is an integer number (1409310554946).

Almost surely, 2^{21512534221311} is an apocalyptic number.

21512534221311 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21512534221311 is a deficient number, since it is larger than the sum of its proper divisors (12310919097393).

21512534221311 is a wasteful number, since it uses less digits than its factorization.

21512534221311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2004709271 (or 2004709264 counting only the distinct ones).

The product of its digits is 14400, while the sum is 33.

Adding to 21512534221311 its reverse (11312243521512), we get a palindrome (32824777742823).

The spelling of 21512534221311 in words is "twenty-one trillion, five hundred twelve billion, five hundred thirty-four million, two hundred twenty-one thousand, three hundred eleven".