21706171670 has 16 divisors (see below), whose sum is σ = 39979740240. Its totient is φ = 8480550624.

The previous prime is 21706171649. The next prime is 21706171673. The reversal of 21706171670 is 7617160712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21706171673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25239305 + ... + 25240164.

It is an arithmetic number, because the mean of its divisors is an integer number (2498733765).

Almost surely, 2^21706171670 is an apocalyptic number.

21706171670 is a deficient number, since it is larger than the sum of its proper divisors (18273568570).

21706171670 is a wasteful number, since it uses less digits than its factorization.

21706171670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50479519.

The product of its (nonzero) digits is 24696, while the sum is 38.

The spelling of 21706171670 in words is "twenty-one billion, seven hundred six million, one hundred seventy-one thousand, six hundred seventy".