21679970911 has 4 divisors (see below), whose sum is σ = 21758238232. Its totient is φ = 21601703592.

The previous prime is 21679970909. The next prime is 21679970929. The reversal of 21679970911 is 11907997612.

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 21679970911 - 2¹ = 21679970909 is a prime.

It is a super-2 number, since 2×21679970911² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21679970941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39133245 + ... + 39133798.

It is an arithmetic number, because the mean of its divisors is an integer number (5439559558).

Almost surely, 2^21679970911 is an apocalyptic number.

21679970911 is a deficient number, since it is larger than the sum of its proper divisors (78267321).

21679970911 is an equidigital number, since it uses as much as digits as its factorization.

21679970911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78267320.

The product of its (nonzero) digits is 428652, while the sum is 52.

The spelling of 21679970911 in words is "twenty-one billion, six hundred seventy-nine million, nine hundred seventy thousand, nine hundred eleven".