21161577776 has 20 divisors (see below), whose sum is σ = 41003235000. Its totient is φ = 10580097792.

The previous prime is 21161577743. The next prime is 21161577851. The reversal of 21161577776 is 67777516112.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 284975 + ... + 351473.

It is an arithmetic number, because the mean of its divisors is an integer number (2050161750).

Almost surely, 2^21161577776 is an apocalyptic number.

It is an amenable number.

21161577776 is a deficient number, since it is larger than the sum of its proper divisors (19841657224).

21161577776 is a wasteful number, since it uses less digits than its factorization.

21161577776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86396 (or 86390 counting only the distinct ones).

The product of its digits is 864360, while the sum is 50.

The spelling of 21161577776 in words is "twenty-one billion, one hundred sixty-one million, five hundred seventy-seven thousand, seven hundred seventy-six".