21205692127747 has 2 divisors, whose sum is σ = 21205692127748. Its totient is φ = 21205692127746.

The previous prime is 21205692127577. The next prime is 21205692127759. The reversal of 21205692127747 is 74772129650212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21205692127747 - 2¹¹ = 21205692125699 is a prime.

It is not a weakly prime, because it can be changed into another prime (21205692127247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10602846063873 + 10602846063874.

It is an arithmetic number, because the mean of its divisors is an integer number (10602846063874).

Almost surely, 2^{21205692127747} is an apocalyptic number.

21205692127747 is a deficient number, since it is larger than the sum of its proper divisors (1).

21205692127747 is an equidigital number, since it uses as much as digits as its factorization.

21205692127747 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5927040, while the sum is 55.

The spelling of 21205692127747 in words is "twenty-one trillion, two hundred five billion, six hundred ninety-two million, one hundred twenty-seven thousand, seven hundred forty-seven".