16579827821 has 2 divisors, whose sum is σ = 16579827822. Its totient is φ = 16579827820.

The previous prime is 16579827793. The next prime is 16579827833. The reversal of 16579827821 is 12872897561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15279432100 + 1300395721 = 123610^2 + 36061^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16579827821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16579827851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8289913910 + 8289913911.

It is an arithmetic number, because the mean of its divisors is an integer number (8289913911).

Almost surely, 2^16579827821 is an apocalyptic number.

It is an amenable number.

16579827821 is a deficient number, since it is larger than the sum of its proper divisors (1).

16579827821 is an equidigital number, since it uses as much as digits as its factorization.

16579827821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3386880, while the sum is 56.

The spelling of 16579827821 in words is "sixteen billion, five hundred seventy-nine million, eight hundred twenty-seven thousand, eight hundred twenty-one".