21313897793 has 2 divisors, whose sum is σ = 21313897794. Its totient is φ = 21313897792.

The previous prime is 21313897783. The next prime is 21313897817. The reversal of 21313897793 is 39779831312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16137383089 + 5176514704 = 127033^2 + 71948^2 .

It is a cyclic number.

It is not a de Polignac number, because 21313897793 - 2¹⁴ = 21313881409 is a prime.

It is not a weakly prime, because it can be changed into another prime (21313897723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656948896 + 10656948897.

It is an arithmetic number, because the mean of its divisors is an integer number (10656948897).

Almost surely, 2^21313897793 is an apocalyptic number.

It is an amenable number.

21313897793 is a deficient number, since it is larger than the sum of its proper divisors (1).

21313897793 is an equidigital number, since it uses as much as digits as its factorization.

21313897793 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1714608, while the sum is 53.

The spelling of 21313897793 in words is "twenty-one billion, three hundred thirteen million, eight hundred ninety-seven thousand, seven hundred ninety-three".