21231412515 has 12 divisors (see below), whose sum is σ = 36801115104. Its totient is φ = 11323419984.

The previous prime is 21231412513. The next prime is 21231412519. The reversal of 21231412515 is 51521413212.

It is a happy number.

21231412515 is a `hidden beast` number, since 2 + 1 + 2 + 3 + 141 + 2 + 515 = 666.

It is not a de Polignac number, because 21231412515 - 2¹ = 21231412513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21231412513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 235904539 + ... + 235904628.

It is an arithmetic number, because the mean of its divisors is an integer number (3066759592).

Almost surely, 2^21231412515 is an apocalyptic number.

21231412515 is a deficient number, since it is larger than the sum of its proper divisors (15569702589).

21231412515 is a wasteful number, since it uses less digits than its factorization.

21231412515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471809178 (or 471809175 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

Adding to 21231412515 its reverse (51521413212), we get a palindrome (72752825727).

The spelling of 21231412515 in words is "twenty-one billion, two hundred thirty-one million, four hundred twelve thousand, five hundred fifteen".