21311151641615 has 256 divisors, whose sum is σ = 32082694963200. Its totient is φ = 13402327910400.

The previous prime is 21311151641609. The next prime is 21311151641641. The reversal of 21311151641615 is 51614615111312.

It is not a de Polignac number, because 21311151641615 - 2⁴ = 21311151641599 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 11451450785 + ... + 11451452645.

It is an arithmetic number, because the mean of its divisors is an integer number (125323027200).

Almost surely, 2^{21311151641615} is an apocalyptic number.

21311151641615 is a deficient number, since it is larger than the sum of its proper divisors (10771543321585).

21311151641615 is a wasteful number, since it uses less digits than its factorization.

21311151641615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2198.

The product of its digits is 21600, while the sum is 38.

Adding to 21311151641615 its reverse (51614615111312), we get a palindrome (72925766752927).

The spelling of 21311151641615 in words is "twenty-one trillion, three hundred eleven billion, one hundred fifty-one million, six hundred forty-one thousand, six hundred fifteen".