16556221801 has 8 divisors (see below), whose sum is σ = 19531764224. Its totient is φ = 13733271360.

The previous prime is 16556221757. The next prime is 16556221831. The reversal of 16556221801 is 10812265561.

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 16556221801 - 2⁹ = 16556221289 is a prime.

It is a super-3 number, since 3×16556221801³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (16556221831) 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, 38147760 + ... + 38148193.

It is an arithmetic number, because the mean of its divisors is an integer number (2441470528).

Almost surely, 2^16556221801 is an apocalyptic number.

It is an amenable number.

16556221801 is a deficient number, since it is larger than the sum of its proper divisors (2975542423).

16556221801 is an equidigital number, since it uses as much as digits as its factorization.

16556221801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76295991.

The product of its (nonzero) digits is 28800, while the sum is 37.

The spelling of 16556221801 in words is "sixteen billion, five hundred fifty-six million, two hundred twenty-one thousand, eight hundred one".