21161235311 has 4 divisors (see below), whose sum is σ = 21477074712. Its totient is φ = 20845395912.

The previous prime is 21161235287. The next prime is 21161235341. The reversal of 21161235311 is 11353216112.

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 21161235311 - 2¹⁸ = 21160973167 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 (21161235341) 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, 157919600 + ... + 157919733.

It is an arithmetic number, because the mean of its divisors is an integer number (5369268678).

Almost surely, 2^21161235311 is an apocalyptic number.

21161235311 is a deficient number, since it is larger than the sum of its proper divisors (315839401).

21161235311 is an equidigital number, since it uses as much as digits as its factorization.

21161235311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315839400.

The product of its digits is 1080, while the sum is 26.

The spelling of 21161235311 in words is "twenty-one billion, one hundred sixty-one million, two hundred thirty-five thousand, three hundred eleven".