21828509567 has 8 divisors (see below), whose sum is σ = 22175356224. Its totient is φ = 21482955648.

The previous prime is 21828509561. The next prime is 21828509579. The reversal of 21828509567 is 76590582812.

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-21828509567 is a prime.

It is a super-2 number, since 2×21828509567² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21828509561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 289118 + ... + 356715.

It is an arithmetic number, because the mean of its divisors is an integer number (2771919528).

Almost surely, 2^21828509567 is an apocalyptic number.

21828509567 is a deficient number, since it is larger than the sum of its proper divisors (346846657).

21828509567 is an equidigital number, since it uses as much as digits as its factorization.

21828509567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646369.

The product of its (nonzero) digits is 2419200, while the sum is 53.

The spelling of 21828509567 in words is "twenty-one billion, eight hundred twenty-eight million, five hundred nine thousand, five hundred sixty-seven".