21066530745 has 32 divisors (see below), whose sum is σ = 36343423872. Its totient is φ = 10358595072.

The previous prime is 21066530741. The next prime is 21066530767. The reversal of 21066530745 is 54703566012.

It is not a de Polignac number, because 21066530745 - 2² = 21066530741 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21066530741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 95949 + ... + 226581.

It is an arithmetic number, because the mean of its divisors is an integer number (1135731996).

Almost surely, 2^21066530745 is an apocalyptic number.

It is an amenable number.

21066530745 is a deficient number, since it is larger than the sum of its proper divisors (15276893127).

21066530745 is a wasteful number, since it uses less digits than its factorization.

21066530745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131481.

The product of its (nonzero) digits is 151200, while the sum is 39.

The spelling of 21066530745 in words is "twenty-one billion, sixty-six million, five hundred thirty thousand, seven hundred forty-five".