16521006566 has 16 divisors (see below), whose sum is σ = 25554507264. Its totient is φ = 8006250504.

The previous prime is 16521006563. The next prime is 16521006577. The reversal of 16521006566 is 66560012561.

It is a super-2 number, since 2×16521006566² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16521006563) 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, 843500 + ... + 862863.

It is an arithmetic number, because the mean of its divisors is an integer number (1597156704).

Almost surely, 2^16521006566 is an apocalyptic number.

16521006566 is a deficient number, since it is larger than the sum of its proper divisors (9033500698).

16521006566 is a wasteful number, since it uses less digits than its factorization.

16521006566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1706515.

The product of its (nonzero) digits is 64800, while the sum is 38.

The spelling of 16521006566 in words is "sixteen billion, five hundred twenty-one million, six thousand, five hundred sixty-six".