215121513423 has 16 divisors (see below), whose sum is σ = 302290081920. Its totient is φ = 135701901216.

The previous prime is 215121513389. The next prime is 215121513433. The reversal of 215121513423 is 324315121512.

It is a happy number.

It is not a de Polignac number, because 215121513423 - 2¹⁰ = 215121512399 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215121513433) 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, 2234640 + ... + 2328917.

It is an arithmetic number, because the mean of its divisors is an integer number (18893130120).

Almost surely, 2^215121513423 is an apocalyptic number.

215121513423 is a deficient number, since it is larger than the sum of its proper divisors (87168568497).

215121513423 is a wasteful number, since it uses less digits than its factorization.

215121513423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4564406.

The product of its digits is 7200, while the sum is 30.

Adding to 215121513423 its reverse (324315121512), we get a palindrome (539436634935).

The spelling of 215121513423 in words is "two hundred fifteen billion, one hundred twenty-one million, five hundred thirteen thousand, four hundred twenty-three".