21027121170 has 32 divisors (see below), whose sum is σ = 55052827200. Its totient is φ = 5097483840.

The previous prime is 21027121151. The next prime is 21027121243. The reversal of 21027121170 is 7112172012.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21027121170.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31858945 + ... + 31859604.

It is an arithmetic number, because the mean of its divisors is an integer number (1720400850).

Almost surely, 2^21027121170 is an apocalyptic number.

21027121170 is an abundant number, since it is smaller than the sum of its proper divisors (34025706030).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21027121170 is a wasteful number, since it uses less digits than its factorization.

21027121170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63718570.

The product of its (nonzero) digits is 392, while the sum is 24.

Adding to 21027121170 its reverse (7112172012), we get a palindrome (28139293182).

The spelling of 21027121170 in words is "twenty-one billion, twenty-seven million, one hundred twenty-one thousand, one hundred seventy".