21666526164034 has 4 divisors (see below), whose sum is σ = 32499789246054. Its totient is φ = 10833263082016.

The previous prime is 21666526164013. The next prime is 21666526164047. The reversal of 21666526164034 is 43046162566612.

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

It can be written as a sum of positive squares in only one way, i.e., 12229323732025 + 9437202432009 = 3497045^2 + 3072003^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5416631541007 + ... + 5416631541010.

Almost surely, 2^{21666526164034} is an apocalyptic number.

21666526164034 is a deficient number, since it is larger than the sum of its proper divisors (10833263082020).

21666526164034 is a wasteful number, since it uses less digits than its factorization.

21666526164034 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10833263082019.

The product of its (nonzero) digits is 7464960, while the sum is 52.

The spelling of 21666526164034 in words is "twenty-one trillion, six hundred sixty-six billion, five hundred twenty-six million, one hundred sixty-four thousand, thirty-four".