21524842917 has 24 divisors (see below), whose sum is σ = 31342311000. Its totient is φ = 14234370048.

The previous prime is 21524842903. The next prime is 21524842919. The reversal of 21524842917 is 71924842512.

21524842917 is a `hidden beast` number, since 2 + 152 + 484 + 2 + 9 + 17 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 19793601 + 21505049316 = 4449^2 + 146646^2 .

It is not a de Polignac number, because 21524842917 - 2¹⁶ = 21524777381 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21524842919) 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, 1020793 + ... + 1041665.

It is an arithmetic number, because the mean of its divisors is an integer number (1305929625).

Almost surely, 2^21524842917 is an apocalyptic number.

It is an amenable number.

21524842917 is a deficient number, since it is larger than the sum of its proper divisors (9817468083).

21524842917 is a wasteful number, since it uses less digits than its factorization.

21524842917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21797 (or 21794 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The spelling of 21524842917 in words is "twenty-one billion, five hundred twenty-four million, eight hundred forty-two thousand, nine hundred seventeen".