21144521115 has 24 divisors (see below), whose sum is σ = 38244005280. Its totient is φ = 10786769664.

The previous prime is 21144521113. The next prime is 21144521117. The reversal of 21144521115 is 51112544112.

21144521115 is a `hidden beast` number, since 2 + 1 + 1 + 445 + 211 + 1 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (21144521113) and next prime (21144521117).

It is not a de Polignac number, because 21144521115 - 2¹ = 21144521113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21144521113) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10213710 + ... + 10215779.

It is an arithmetic number, because the mean of its divisors is an integer number (1593500220).

Almost surely, 2^21144521115 is an apocalyptic number.

21144521115 is a deficient number, since it is larger than the sum of its proper divisors (17099484165).

21144521115 is a wasteful number, since it uses less digits than its factorization.

21144521115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20429523 (or 20429520 counting only the distinct ones).

The product of its digits is 1600, while the sum is 27.

The spelling of 21144521115 in words is "twenty-one billion, one hundred forty-four million, five hundred twenty-one thousand, one hundred fifteen".