16505615653 has 4 divisors (see below), whose sum is σ = 16507755628. Its totient is φ = 16503475680.

The previous prime is 16505615641. The next prime is 16505615657. The reversal of 16505615653 is 35651650561.

It is a happy number.

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 7708488804 + 8797126849 = 87798^2 + 93793^2 .

It is a cyclic number.

It is not a de Polignac number, because 16505615653 - 2²⁹ = 15968744741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16505615657) 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, 1058376 + ... + 1073857.

It is an arithmetic number, because the mean of its divisors is an integer number (4126938907).

Almost surely, 2^16505615653 is an apocalyptic number.

It is an amenable number.

16505615653 is a deficient number, since it is larger than the sum of its proper divisors (2139975).

16505615653 is an equidigital number, since it uses as much as digits as its factorization.

16505615653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2139974.

The product of its (nonzero) digits is 405000, while the sum is 43.

The spelling of 16505615653 in words is "sixteen billion, five hundred five million, six hundred fifteen thousand, six hundred fifty-three".