21518680522 has 8 divisors (see below), whose sum is σ = 32445264996. Its totient is φ = 10703592192.

The previous prime is 21518680511. The next prime is 21518680537. The reversal of 21518680522 is 22508681512.

It can be written as a sum of positive squares in 2 ways, for example, as 20672975961 + 845704561 = 143781^2 + 29081^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21518680522² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27873553 + ... + 27874324.

Almost surely, 2^21518680522 is an apocalyptic number.

21518680522 is a deficient number, since it is larger than the sum of its proper divisors (10926584474).

21518680522 is a wasteful number, since it uses less digits than its factorization.

21518680522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55748072.

The product of its (nonzero) digits is 76800, while the sum is 40.

The spelling of 21518680522 in words is "twenty-one billion, five hundred eighteen million, six hundred eighty thousand, five hundred twenty-two".