16564735412521 has 4 divisors (see below), whose sum is σ = 16657275834000. Its totient is φ = 16472194991044.

The previous prime is 16564735412513. The next prime is 16564735412527. The reversal of 16564735412521 is 12521453746561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16564735412521 - 2³ = 16564735412513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16564735412527) 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, 46270210471 + ... + 46270210828.

It is an arithmetic number, because the mean of its divisors is an integer number (4164318958500).

Almost surely, 2^{16564735412521} is an apocalyptic number.

It is an amenable number.

16564735412521 is a deficient number, since it is larger than the sum of its proper divisors (92540421479).

16564735412521 is an equidigital number, since it uses as much as digits as its factorization.

16564735412521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92540421478.

The product of its digits is 6048000, while the sum is 52.

The spelling of 16564735412521 in words is "sixteen trillion, five hundred sixty-four billion, seven hundred thirty-five million, four hundred twelve thousand, five hundred twenty-one".