21027129198811 has 4 divisors (see below), whose sum is σ = 21027962674800. Its totient is φ = 21026295722824.

The previous prime is 21027129198781. The next prime is 21027129198857. The reversal of 21027129198811 is 11889192172012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21027129198811 - 2¹⁷ = 21027129067739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21027129195811) 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, 416700151 + ... + 416750608.

It is an arithmetic number, because the mean of its divisors is an integer number (5256990668700).

Almost surely, 2^{21027129198811} is an apocalyptic number.

21027129198811 is a deficient number, since it is larger than the sum of its proper divisors (833475989).

21027129198811 is an equidigital number, since it uses as much as digits as its factorization.

21027129198811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833475988.

The product of its (nonzero) digits is 290304, while the sum is 52.

The spelling of 21027129198811 in words is "twenty-one trillion, twenty-seven billion, one hundred twenty-nine million, one hundred ninety-eight thousand, eight hundred eleven".