21111121315 has 4 divisors (see below), whose sum is σ = 25333345584. Its totient is φ = 16888897048.

The previous prime is 21111121301. The next prime is 21111121333. The reversal of 21111121315 is 51312111112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21111121315 - 2¹⁵ = 21111088547 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111121292 and 21111121301.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2111112127 + ... + 2111112136.

It is an arithmetic number, because the mean of its divisors is an integer number (6333336396).

Almost surely, 2^21111121315 is an apocalyptic number.

21111121315 is a deficient number, since it is larger than the sum of its proper divisors (4222224269).

21111121315 is an equidigital number, since it uses as much as digits as its factorization.

21111121315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4222224268.

The product of its digits is 60, while the sum is 19.

Adding to 21111121315 its reverse (51312111112), we get a palindrome (72423232427).

The spelling of 21111121315 in words is "twenty-one billion, one hundred eleven million, one hundred twenty-one thousand, three hundred fifteen".