16505464321 has 4 divisors (see below), whose sum is σ = 16515610672. Its totient is φ = 16495317972.

The previous prime is 16505464307. The next prime is 16505464333. The reversal of 16505464321 is 12346450561.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12346450561 = 37 ⋅333687853.

It is a cyclic number.

It is not a de Polignac number, because 16505464321 - 2¹¹ = 16505462273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16505464621) 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, 5070735 + ... + 5073988.

It is an arithmetic number, because the mean of its divisors is an integer number (4128902668).

Almost surely, 2^16505464321 is an apocalyptic number.

It is an amenable number.

16505464321 is a deficient number, since it is larger than the sum of its proper divisors (10146351).

16505464321 is a wasteful number, since it uses less digits than its factorization.

16505464321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10146350.

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 16505464321 in words is "sixteen billion, five hundred five million, four hundred sixty-four thousand, three hundred twenty-one".