21634726011 has 4 divisors (see below), whose sum is σ = 28846301352. Its totient is φ = 14423150672.

The previous prime is 21634725977. The next prime is 21634726027. The reversal of 21634726011 is 11062743612.

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 21634726011 - 2⁹ = 21634725499 is a prime.

It is a super-2 number, since 2×21634726011² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21634726051) 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, 3605787666 + ... + 3605787671.

It is an arithmetic number, because the mean of its divisors is an integer number (7211575338).

Almost surely, 2^21634726011 is an apocalyptic number.

21634726011 is a deficient number, since it is larger than the sum of its proper divisors (7211575341).

21634726011 is an equidigital number, since it uses as much as digits as its factorization.

21634726011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7211575340.

The product of its (nonzero) digits is 12096, while the sum is 33.

The spelling of 21634726011 in words is "twenty-one billion, six hundred thirty-four million, seven hundred twenty-six thousand, eleven".