21168853197 has 4 divisors (see below), whose sum is σ = 28225137600. Its totient is φ = 14112568796.

The previous prime is 21168853159. The next prime is 21168853201. The reversal of 21168853197 is 79135886112.

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 21168853197 - 2⁸ = 21168852941 is a prime.

It is a super-2 number, since 2×21168853197² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21168853117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3528142197 + ... + 3528142202.

It is an arithmetic number, because the mean of its divisors is an integer number (7056284400).

Almost surely, 2^21168853197 is an apocalyptic number.

It is an amenable number.

21168853197 is a deficient number, since it is larger than the sum of its proper divisors (7056284403).

21168853197 is an equidigital number, since it uses as much as digits as its factorization.

21168853197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7056284402.

The product of its digits is 725760, while the sum is 51.

The spelling of 21168853197 in words is "twenty-one billion, one hundred sixty-eight million, eight hundred fifty-three thousand, one hundred ninety-seven".