16521002553 has 16 divisors (see below), whose sum is σ = 24174452736. Its totient is φ = 9952769040.

The previous prime is 16521002507. The next prime is 16521002573. The reversal of 16521002553 is 35520012561.

It is a happy number.

It is not a de Polignac number, because 16521002553 - 2¹⁰ = 16521001529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16521002553.

It is not an unprimeable number, because it can be changed into a prime (16521002573) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1493401 + ... + 1504422.

It is an arithmetic number, because the mean of its divisors is an integer number (1510903296).

Almost surely, 2^16521002553 is an apocalyptic number.

It is an amenable number.

16521002553 is a deficient number, since it is larger than the sum of its proper divisors (7653450183).

16521002553 is a wasteful number, since it uses less digits than its factorization.

16521002553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2998004.

The product of its (nonzero) digits is 9000, while the sum is 30.

The spelling of 16521002553 in words is "sixteen billion, five hundred twenty-one million, two thousand, five hundred fifty-three".