21666364536346 has 8 divisors (see below), whose sum is σ = 32521491134964. Its totient is φ = 10825867491360.

The previous prime is 21666364536233. The next prime is 21666364536347. The reversal of 21666364536346 is 64363546366612.

It can be written as a sum of positive squares in 2 ways, for example, as 21577056202321 + 89308334025 = 4645111^2 + 298845^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21666364536347) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3657384705 + ... + 3657390628.

Almost surely, 2^{21666364536346} is an apocalyptic number.

21666364536346 is a deficient number, since it is larger than the sum of its proper divisors (10855126598618).

21666364536346 is a wasteful number, since it uses less digits than its factorization.

21666364536346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7314776816.

The product of its digits is 201553920, while the sum is 61.

The spelling of 21666364536346 in words is "twenty-one trillion, six hundred sixty-six billion, three hundred sixty-four million, five hundred thirty-six thousand, three hundred forty-six".