16505532521 has 8 divisors (see below), whose sum is σ = 16989450240. Its totient is φ = 16027145568.

The previous prime is 16505532493. The next prime is 16505532557. The reversal of 16505532521 is 12523550561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16505532521 - 2⁶ = 16505532457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16505532581) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1376636 + ... + 1388573.

It is an arithmetic number, because the mean of its divisors is an integer number (2123681280).

Almost surely, 2^16505532521 is an apocalyptic number.

It is an amenable number.

16505532521 is a deficient number, since it is larger than the sum of its proper divisors (483917719).

16505532521 is a wasteful number, since it uses less digits than its factorization.

16505532521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2765383.

The product of its (nonzero) digits is 45000, while the sum is 35.

The spelling of 16505532521 in words is "sixteen billion, five hundred five million, five hundred thirty-two thousand, five hundred twenty-one".