21365144156311 has 4 divisors (see below), whose sum is σ = 21367485038032. Its totient is φ = 21362803274592.

The previous prime is 21365144156309. The next prime is 21365144156329. The reversal of 21365144156311 is 11365144156312.

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 21365144156311 - 2¹ = 21365144156309 is a prime.

It is a super-2 number, since 2×21365144156311² (a number of 27 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 (21365144156371) 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, 1170427170 + ... + 1170445423.

It is an arithmetic number, because the mean of its divisors is an integer number (5341871259508).

Almost surely, 2^{21365144156311} is an apocalyptic number.

21365144156311 is a deficient number, since it is larger than the sum of its proper divisors (2340881721).

21365144156311 is an equidigital number, since it uses as much as digits as its factorization.

21365144156311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2340881720.

The product of its digits is 259200, while the sum is 43.

Subtracting from 21365144156311 its reverse (11365144156312), we obtain a palindrome (9999999999999).

The spelling of 21365144156311 in words is "twenty-one trillion, three hundred sixty-five billion, one hundred forty-four million, one hundred fifty-six thousand, three hundred eleven".