21705327267 has 16 divisors (see below), whose sum is σ = 31209534720. Its totient is φ = 13338734112.

The previous prime is 21705327253. The next prime is 21705327289. The reversal of 21705327267 is 76272350712.

It is a happy number.

It is not a de Polignac number, because 21705327267 - 2¹⁶ = 21705261731 is a prime.

It is a super-2 number, since 2×21705327267² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21705327067) 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, 354417 + ... + 411122.

It is an arithmetic number, because the mean of its divisors is an integer number (1950595920).

Almost surely, 2^21705327267 is an apocalyptic number.

21705327267 is a deficient number, since it is larger than the sum of its proper divisors (9504207453).

21705327267 is a wasteful number, since it uses less digits than its factorization.

21705327267 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 766282.

The product of its (nonzero) digits is 246960, while the sum is 42.

Adding to 21705327267 its reverse (76272350712), we get a palindrome (97977677979).

The spelling of 21705327267 in words is "twenty-one billion, seven hundred five million, three hundred twenty-seven thousand, two hundred sixty-seven".