21066530699 has 4 divisors (see below), whose sum is σ = 21092571720. Its totient is φ = 21040489680.

The previous prime is 21066530669. The next prime is 21066530701. The reversal of 21066530699 is 99603566012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21066530699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21066530609) 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, 13019297 + ... + 13020914.

It is an arithmetic number, because the mean of its divisors is an integer number (5273142930).

Almost surely, 2^21066530699 is an apocalyptic number.

21066530699 is a deficient number, since it is larger than the sum of its proper divisors (26041021).

21066530699 is an equidigital number, since it uses as much as digits as its factorization.

21066530699 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26041020.

The product of its (nonzero) digits is 524880, while the sum is 47.

The spelling of 21066530699 in words is "twenty-one billion, sixty-six million, five hundred thirty thousand, six hundred ninety-nine".