21115230015 has 16 divisors (see below), whose sum is σ = 36855674496. Its totient is φ = 10237687200.

The previous prime is 21115230013. The next prime is 21115230061. The reversal of 21115230015 is 51003251112.

It is not a de Polignac number, because 21115230015 - 2¹ = 21115230013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21115229973 and 21115230000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115230013) 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, 63985381 + ... + 63985710.

It is an arithmetic number, because the mean of its divisors is an integer number (2303479656).

Almost surely, 2^21115230015 is an apocalyptic number.

21115230015 is a deficient number, since it is larger than the sum of its proper divisors (15740444481).

21115230015 is a wasteful number, since it uses less digits than its factorization.

21115230015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127971110.

The product of its (nonzero) digits is 300, while the sum is 21.

Adding to 21115230015 its reverse (51003251112), we get a palindrome (72118481127).

The spelling of 21115230015 in words is "twenty-one billion, one hundred fifteen million, two hundred thirty thousand, fifteen".