21071803170 has 64 divisors (see below), whose sum is σ = 55604330496. Its totient is φ = 5068082880.

The previous prime is 21071803147. The next prime is 21071803177. The reversal of 21071803170 is 7130817012.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (21071803177) 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 31 ways as a sum of consecutive naturals, for example, 209484 + ... + 293303.

It is an arithmetic number, because the mean of its divisors is an integer number (868817664).

Almost surely, 2^21071803170 is an apocalyptic number.

21071803170 is an abundant number, since it is smaller than the sum of its proper divisors (34532527326).

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

21071803170 is a wasteful number, since it uses less digits than its factorization.

21071803170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502935.

The product of its (nonzero) digits is 2352, while the sum is 30.

The spelling of 21071803170 in words is "twenty-one billion, seventy-one million, eight hundred three thousand, one hundred seventy".