21336516745 has 4 divisors (see below), whose sum is σ = 25603820100. Its totient is φ = 17069213392.

The previous prime is 21336516739. The next prime is 21336516767. The reversal of 21336516745 is 54761563312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15453473344 + 5883043401 = 124312^2 + 76701^2 .

It is a cyclic number.

It is not a de Polignac number, because 21336516745 - 2³ = 21336516737 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2133651670 + ... + 2133651679.

It is an arithmetic number, because the mean of its divisors is an integer number (6400955025).

Almost surely, 2^21336516745 is an apocalyptic number.

It is an amenable number.

21336516745 is a deficient number, since it is larger than the sum of its proper divisors (4267303355).

21336516745 is an equidigital number, since it uses as much as digits as its factorization.

21336516745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4267303354.

The product of its digits is 453600, while the sum is 43.

The spelling of 21336516745 in words is "twenty-one billion, three hundred thirty-six million, five hundred sixteen thousand, seven hundred forty-five".