21170729576 has 16 divisors (see below), whose sum is σ = 39698575200. Its totient is φ = 10584442864.

The previous prime is 21170729551. The next prime is 21170729579. The reversal of 21170729576 is 67592707112.

It is a super-2 number, since 2×21170729576² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21170729576.

It is not an unprimeable number, because it can be changed into a prime (21170729579) 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, 12230 + ... + 206133.

It is an arithmetic number, because the mean of its divisors is an integer number (2481160950).

Almost surely, 2^21170729576 is an apocalyptic number.

It is an amenable number.

21170729576 is a deficient number, since it is larger than the sum of its proper divisors (18527845624).

21170729576 is a wasteful number, since it uses less digits than its factorization.

21170729576 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230488 (or 230484 counting only the distinct ones).

The product of its (nonzero) digits is 370440, while the sum is 47.

The spelling of 21170729576 in words is "twenty-one billion, one hundred seventy million, seven hundred twenty-nine thousand, five hundred seventy-six".