21170042176 has 14 divisors (see below), whose sum is σ = 42009302570. Its totient is φ = 10585021056.

The previous prime is 21170042111. The next prime is 21170042189. The reversal of 21170042176 is 67124007112.

It can be written as a sum of positive squares in only one way, i.e., 21148139776 + 21902400 = 145424^2 + 4680^2 .

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 165390891 + ... + 165391018.

Almost surely, 2^21170042176 is an apocalyptic number.

It is an amenable number.

21170042176 is a deficient number, since it is larger than the sum of its proper divisors (20839260394).

21170042176 is an equidigital number, since it uses as much as digits as its factorization.

21170042176 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330781921 (or 330781911 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 31.

Adding to 21170042176 its reverse (67124007112), we get a palindrome (88294049288).

The spelling of 21170042176 in words is "twenty-one billion, one hundred seventy million, forty-two thousand, one hundred seventy-six".