21610548166 has 4 divisors (see below), whose sum is σ = 32415822252. Its totient is φ = 10805274082.

The previous prime is 21610548161. The next prime is 21610548191. The reversal of 21610548166 is 66184501612.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21610548161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5402637040 + ... + 5402637043.

It is an arithmetic number, because the mean of its divisors is an integer number (8103955563).

Almost surely, 2^21610548166 is an apocalyptic number.

21610548166 is a deficient number, since it is larger than the sum of its proper divisors (10805274086).

21610548166 is a wasteful number, since it uses less digits than its factorization.

21610548166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10805274085.

The product of its (nonzero) digits is 69120, while the sum is 40.

The spelling of 21610548166 in words is "twenty-one billion, six hundred ten million, five hundred forty-eight thousand, one hundred sixty-six".