21013207798393 has 4 divisors (see below), whose sum is σ = 21093105927168. Its totient is φ = 20933309669620.

The previous prime is 21013207798379. The next prime is 21013207798423. The reversal of 21013207798393 is 39389770231012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21013207798393 - 2⁴¹ = 18814184542841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21013207768393) 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, 39949063993 + ... + 39949064518.

It is an arithmetic number, because the mean of its divisors is an integer number (5273276481792).

Almost surely, 2^{21013207798393} is an apocalyptic number.

It is an amenable number.

21013207798393 is a deficient number, since it is larger than the sum of its proper divisors (79898128775).

21013207798393 is an equidigital number, since it uses as much as digits as its factorization.

21013207798393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79898128774.

The product of its (nonzero) digits is 3429216, while the sum is 55.

The spelling of 21013207798393 in words is "twenty-one trillion, thirteen billion, two hundred seven million, seven hundred ninety-eight thousand, three hundred ninety-three".