16620405845 has 4 divisors (see below), whose sum is σ = 19944487020. Its totient is φ = 13296324672.

The previous prime is 16620405829. The next prime is 16620405859. The reversal of 16620405845 is 54850402661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54850402661 = 229 ⋅239521409.

It can be written as a sum of positive squares in 2 ways, for example, as 6752566276 + 9867839569 = 82174^2 + 99337^2 .

It is a cyclic number.

It is not a de Polignac number, because 16620405845 - 2⁴ = 16620405829 is a prime.

It is a congruent number.

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 in 3 ways as a sum of consecutive naturals, for example, 1662040580 + ... + 1662040589.

It is an arithmetic number, because the mean of its divisors is an integer number (4986121755).

Almost surely, 2^16620405845 is an apocalyptic number.

It is an amenable number.

16620405845 is a deficient number, since it is larger than the sum of its proper divisors (3324081175).

16620405845 is an equidigital number, since it uses as much as digits as its factorization.

16620405845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3324081174.

The product of its (nonzero) digits is 230400, while the sum is 41.

The spelling of 16620405845 in words is "sixteen billion, six hundred twenty million, four hundred five thousand, eight hundred forty-five".