21537018719 has 8 divisors (see below), whose sum is σ = 23283264240. Its totient is φ = 19852045056.

The previous prime is 21537018697. The next prime is 21537018721. The reversal of 21537018719 is 91781073512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21537018719 is a prime.

It is a super-2 number, since 2×21537018719² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21537018719.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21537018799) 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 7 ways as a sum of consecutive naturals, for example, 15317234 + ... + 15318639.

It is an arithmetic number, because the mean of its divisors is an integer number (2910408030).

Almost surely, 2^21537018719 is an apocalyptic number.

21537018719 is a deficient number, since it is larger than the sum of its proper divisors (1746245521).

21537018719 is a wasteful number, since it uses less digits than its factorization.

21537018719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30635929.

The product of its (nonzero) digits is 105840, while the sum is 44.

The spelling of 21537018719 in words is "twenty-one billion, five hundred thirty-seven million, eighteen thousand, seven hundred nineteen".