21267621545759 has 4 divisors (see below), whose sum is σ = 21267633578304. Its totient is φ = 21267609513216.

The previous prime is 21267621545719. The next prime is 21267621545873. The reversal of 21267621545759 is 95754512676212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21267621545759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21267621545719) 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, 2787362 + ... + 7092575.

It is an arithmetic number, because the mean of its divisors is an integer number (5316908394576).

Almost surely, 2^{21267621545759} is an apocalyptic number.

21267621545759 is a deficient number, since it is larger than the sum of its proper divisors (12032545).

21267621545759 is an equidigital number, since it uses as much as digits as its factorization.

21267621545759 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12032544.

The product of its digits is 63504000, while the sum is 62.

The spelling of 21267621545759 in words is "twenty-one trillion, two hundred sixty-seven billion, six hundred twenty-one million, five hundred forty-five thousand, seven hundred fifty-nine".