21322731517 has 16 divisors (see below), whose sum is σ = 22563094320. Its totient is φ = 20126126592.

The previous prime is 21322731481. The next prime is 21322731557. The reversal of 21322731517 is 71513722312.

It can be written as a sum of positive squares in 8 ways, for example, as 4005750681 + 17316980836 = 63291^2 + 131594^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21322731517 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21322731557) 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, 113443 + ... + 235615.

It is an arithmetic number, because the mean of its divisors is an integer number (1410193395).

Almost surely, 2^21322731517 is an apocalyptic number.

It is an amenable number.

21322731517 is a deficient number, since it is larger than the sum of its proper divisors (1240362803).

21322731517 is a wasteful number, since it uses less digits than its factorization.

21322731517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122352.

The product of its digits is 17640, while the sum is 34.

The spelling of 21322731517 in words is "twenty-one billion, three hundred twenty-two million, seven hundred thirty-one thousand, five hundred seventeen".