21311151733 has 2 divisors, whose sum is σ = 21311151734. Its totient is φ = 21311151732.

The previous prime is 21311151731. The next prime is 21311151793. The reversal of 21311151733 is 33715111312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12038039524 + 9273112209 = 109718^2 + 96297^2 .

It is a cyclic number.

It is not a de Polignac number, because 21311151733 - 2¹ = 21311151731 is a prime.

Together with 21311151731, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21311151731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655575866 + 10655575867.

It is an arithmetic number, because the mean of its divisors is an integer number (10655575867).

Almost surely, 2^21311151733 is an apocalyptic number.

It is an amenable number.

21311151733 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311151733 is an equidigital number, since it uses as much as digits as its factorization.

21311151733 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1890, while the sum is 28.

The spelling of 21311151733 in words is "twenty-one billion, three hundred eleven million, one hundred fifty-one thousand, seven hundred thirty-three".