16554221797 has 4 divisors (see below), whose sum is σ = 16622911756. Its totient is φ = 16485531840.

The previous prime is 16554221773. The next prime is 16554221833. The reversal of 16554221797 is 79712245561.

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 13214422116 + 3339799681 = 114954^2 + 57791^2 .

It is a cyclic number.

It is not a de Polignac number, because 16554221797 - 2⁷ = 16554221669 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16554221797.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16554227797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34344618 + ... + 34345099.

It is an arithmetic number, because the mean of its divisors is an integer number (4155727939).

Almost surely, 2^16554221797 is an apocalyptic number.

It is an amenable number.

16554221797 is a deficient number, since it is larger than the sum of its proper divisors (68689959).

16554221797 is an equidigital number, since it uses as much as digits as its factorization.

16554221797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68689958.

The product of its digits is 1058400, while the sum is 49.

The spelling of 16554221797 in words is "sixteen billion, five hundred fifty-four million, two hundred twenty-one thousand, seven hundred ninety-seven".