21214026166 has 4 divisors (see below), whose sum is σ = 31821039252. Its totient is φ = 10607013082.

The previous prime is 21214026151. The next prime is 21214026209. The reversal of 21214026166 is 66162041212.

It is a happy number.

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

It is a Smith number, since the sum of its digits (31) 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 an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5303506540 + ... + 5303506543.

It is an arithmetic number, because the mean of its divisors is an integer number (7955259813).

Almost surely, 2^21214026166 is an apocalyptic number.

21214026166 is a deficient number, since it is larger than the sum of its proper divisors (10607013086).

21214026166 is a wasteful number, since it uses less digits than its factorization.

21214026166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10607013085.

The product of its (nonzero) digits is 6912, while the sum is 31.

Adding to 21214026166 its reverse (66162041212), we get a palindrome (87376067378).

The spelling of 21214026166 in words is "twenty-one billion, two hundred fourteen million, twenty-six thousand, one hundred sixty-six".