21311100015 has 16 divisors (see below), whose sum is σ = 34675689600. Its totient is φ = 11173276832.

The previous prime is 21311099987. The next prime is 21311100037. The reversal of 21311100015 is 51000111312.

It is a cyclic number.

It is not a de Polignac number, because 21311100015 - 2²⁰ = 21310051439 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a junction number, because it is equal to n+sod(n) for n = 21311099967 and 21311100003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12039285 + ... + 12041054.

It is an arithmetic number, because the mean of its divisors is an integer number (2167230600).

Almost surely, 2^21311100015 is an apocalyptic number.

21311100015 is a deficient number, since it is larger than the sum of its proper divisors (13364589585).

21311100015 is a wasteful number, since it uses less digits than its factorization.

21311100015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24080406.

The product of its (nonzero) digits is 30, while the sum is 15.

Adding to 21311100015 its reverse (51000111312), we get a palindrome (72311211327).

The spelling of 21311100015 in words is "twenty-one billion, three hundred eleven million, one hundred thousand, fifteen".