21729823311 has 8 divisors (see below), whose sum is σ = 33112111744. Its totient is φ = 12417041880.

The previous prime is 21729823301. The next prime is 21729823343. The reversal of 21729823311 is 11332892712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21729823311 - 2¹⁰ = 21729822287 is a prime.

It is a super-2 number, since 2×21729823311² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21729823311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21729823301) 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, 517376725 + ... + 517376766.

It is an arithmetic number, because the mean of its divisors is an integer number (4139013968).

Almost surely, 2^21729823311 is an apocalyptic number.

21729823311 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21729823311 is a deficient number, since it is larger than the sum of its proper divisors (11382288433).

21729823311 is a wasteful number, since it uses less digits than its factorization.

21729823311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1034753501.

The product of its digits is 36288, while the sum is 39.

The spelling of 21729823311 in words is "twenty-one billion, seven hundred twenty-nine million, eight hundred twenty-three thousand, three hundred eleven".