16505051645 has 4 divisors (see below), whose sum is σ = 19806061980. Its totient is φ = 13204041312.

The previous prime is 16505051639. The next prime is 16505051659. The reversal of 16505051645 is 54615050561.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54615050561 = 17 ⋅3212650033.

It can be written as a sum of positive squares in 2 ways, for example, as 2604877444 + 13900174201 = 51038^2 + 117899^2 .

It is a cyclic number.

It is not a de Polignac number, because 16505051645 - 2¹⁶ = 16504986109 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16505051599 and 16505051608.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1650505160 + ... + 1650505169.

It is an arithmetic number, because the mean of its divisors is an integer number (4951515495).

Almost surely, 2^16505051645 is an apocalyptic number.

It is an amenable number.

16505051645 is a deficient number, since it is larger than the sum of its proper divisors (3301010335).

16505051645 is an equidigital number, since it uses as much as digits as its factorization.

16505051645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3301010334.

The product of its (nonzero) digits is 90000, while the sum is 38.

It can be divided in two parts, 165050516 and 45, that added together give a palindrome (165050561).

The spelling of 16505051645 in words is "sixteen billion, five hundred five million, fifty-one thousand, six hundred forty-five".