21064985267 has 4 divisors (see below), whose sum is σ = 21090093360. Its totient is φ = 21039877176.

The previous prime is 21064985261. The next prime is 21064985269. The reversal of 21064985267 is 76258946012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21064985267 - 2¹⁶ = 21064919731 is a prime.

It is a super-2 number, since 2×21064985267² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21064985261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12552788 + ... + 12554465.

It is an arithmetic number, because the mean of its divisors is an integer number (5272523340).

Almost surely, 2^21064985267 is an apocalyptic number.

21064985267 is a deficient number, since it is larger than the sum of its proper divisors (25108093).

21064985267 is an equidigital number, since it uses as much as digits as its factorization.

21064985267 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25108092.

The product of its (nonzero) digits is 1451520, while the sum is 50.

The spelling of 21064985267 in words is "twenty-one billion, sixty-four million, nine hundred eighty-five thousand, two hundred sixty-seven".