21612231456005 has 16 divisors (see below), whose sum is σ = 25945115697984. Its totient is φ = 17282827180800.

The previous prime is 21612231455981. The next prime is 21612231456007. The reversal of 21612231456005 is 50065413221612.

It is not a de Polignac number, because 21612231456005 - 2²⁰ = 21612230407429 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21612231456005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21612231456007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 495296669 + ... + 495340301.

It is an arithmetic number, because the mean of its divisors is an integer number (1621569731124).

Almost surely, 2^{21612231456005} is an apocalyptic number.

It is an amenable number.

21612231456005 is a deficient number, since it is larger than the sum of its proper divisors (4332884241979).

21612231456005 is a wasteful number, since it uses less digits than its factorization.

21612231456005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81236.

The product of its (nonzero) digits is 86400, while the sum is 38.

Adding to 21612231456005 its reverse (50065413221612), we get a palindrome (71677644677617).

The spelling of 21612231456005 in words is "twenty-one trillion, six hundred twelve billion, two hundred thirty-one million, four hundred fifty-six thousand, five".