16426566621 has 6 divisors (see below), whose sum is σ = 23727262910. Its totient is φ = 10951044408.

The previous prime is 16426566619. The next prime is 16426566643. The reversal of 16426566621 is 12666562461.

It can be written as a sum of positive squares in only one way, i.e., 15175529721 + 1251036900 = 123189^2 + 35370^2 .

It is not a de Polignac number, because 16426566621 - 2¹ = 16426566619 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16426566521) 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 5 ways as a sum of consecutive naturals, for example, 912587026 + ... + 912587043.

Almost surely, 2^16426566621 is an apocalyptic number.

It is an amenable number.

16426566621 is a deficient number, since it is larger than the sum of its proper divisors (7300696289).

16426566621 is a wasteful number, since it uses less digits than its factorization.

16426566621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1825174075 (or 1825174072 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The spelling of 16426566621 in words is "sixteen billion, four hundred twenty-six million, five hundred sixty-six thousand, six hundred twenty-one".