21226959817 has 4 divisors (see below), whose sum is σ = 24259382656. Its totient is φ = 18194536980.

The previous prime is 21226959757. The next prime is 21226959823. The reversal of 21226959817 is 71895962212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21226959817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21226959827) 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 3 ways as a sum of consecutive naturals, for example, 1516211409 + ... + 1516211422.

It is an arithmetic number, because the mean of its divisors is an integer number (6064845664).

Almost surely, 2^21226959817 is an apocalyptic number.

It is an amenable number.

21226959817 is a deficient number, since it is larger than the sum of its proper divisors (3032422839).

21226959817 is an equidigital number, since it uses as much as digits as its factorization.

21226959817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3032422838.

The product of its digits is 1088640, while the sum is 52.

The spelling of 21226959817 in words is "twenty-one billion, two hundred twenty-six million, nine hundred fifty-nine thousand, eight hundred seventeen".