21311505343 has 2 divisors, whose sum is σ = 21311505344. Its totient is φ = 21311505342.

The previous prime is 21311505307. The next prime is 21311505349. The reversal of 21311505343 is 34350511312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21311505343 - 2³³ = 12721570751 is a prime.

It is a super-5 number, since 5×21311505343⁵ (a number of 53 digits) contains 55555 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21311505349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655752671 + 10655752672.

It is an arithmetic number, because the mean of its divisors is an integer number (10655752672).

Almost surely, 2^21311505343 is an apocalyptic number.

21311505343 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311505343 is an equidigital number, since it uses as much as digits as its factorization.

21311505343 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 28.

The spelling of 21311505343 in words is "twenty-one billion, three hundred eleven million, five hundred five thousand, three hundred forty-three".