21258466166006 has 4 divisors (see below), whose sum is σ = 31887699249012. Its totient is φ = 10629233083002.

The previous prime is 21258466165991. The next prime is 21258466166009. The reversal of 21258466166006 is 60066166485212.

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

It is a super-2 number, since 2×21258466166006² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21258466166009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5314616541500 + ... + 5314616541503.

It is an arithmetic number, because the mean of its divisors is an integer number (7971924812253).

Almost surely, 2^{21258466166006} is an apocalyptic number.

21258466166006 is a deficient number, since it is larger than the sum of its proper divisors (10629233083006).

21258466166006 is a wasteful number, since it uses less digits than its factorization.

21258466166006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10629233083005.

The product of its (nonzero) digits is 4976640, while the sum is 53.

The spelling of 21258466166006 in words is "twenty-one trillion, two hundred fifty-eight billion, four hundred sixty-six million, one hundred sixty-six thousand, six".