21168158777 has 8 divisors (see below), whose sum is σ = 21465330432. Its totient is φ = 20872598400.

The previous prime is 21168158773. The next prime is 21168158801. The reversal of 21168158777 is 77785186112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21168158777 - 2² = 21168158773 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21168158771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 376349 + ... + 428922.

It is an arithmetic number, because the mean of its divisors is an integer number (2683166304).

Almost surely, 2^21168158777 is an apocalyptic number.

It is an amenable number.

21168158777 is a deficient number, since it is larger than the sum of its proper divisors (297171655).

21168158777 is an equidigital number, since it uses as much as digits as its factorization.

21168158777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 805639.

The product of its digits is 1317120, while the sum is 53.

The spelling of 21168158777 in words is "twenty-one billion, one hundred sixty-eight million, one hundred fifty-eight thousand, seven hundred seventy-seven".