21155015113315 has 16 divisors (see below), whose sum is σ = 26205068802816. Its totient is φ = 16377984432000.

The previous prime is 21155015113313. The next prime is 21155015113339. The reversal of 21155015113315 is 51331151055112.

It is not a de Polignac number, because 21155015113315 - 2¹ = 21155015113313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21155015113313) 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, 43713165 + ... + 44194465.

It is an arithmetic number, because the mean of its divisors is an integer number (1637816800176).

Almost surely, 2^{21155015113315} is an apocalyptic number.

21155015113315 is a deficient number, since it is larger than the sum of its proper divisors (5050053689501).

21155015113315 is a wasteful number, since it uses less digits than its factorization.

21155015113315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764910.

The product of its (nonzero) digits is 11250, while the sum is 34.

Adding to 21155015113315 its reverse (51331151055112), we get a palindrome (72486166168427).

The spelling of 21155015113315 in words is "twenty-one trillion, one hundred fifty-five billion, fifteen million, one hundred thirteen thousand, three hundred fifteen".