16521570349 has 2 divisors, whose sum is σ = 16521570350. Its totient is φ = 16521570348.

The previous prime is 16521570259. The next prime is 16521570407. The reversal of 16521570349 is 94307512561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13772665449 + 2748904900 = 117357^2 + 52430^2 .

It is a cyclic number.

It is not a de Polignac number, because 16521570349 - 2⁹ = 16521569837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16521570449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8260785174 + 8260785175.

It is an arithmetic number, because the mean of its divisors is an integer number (8260785175).

Almost surely, 2^16521570349 is an apocalyptic number.

It is an amenable number.

16521570349 is a deficient number, since it is larger than the sum of its proper divisors (1).

16521570349 is an equidigital number, since it uses as much as digits as its factorization.

16521570349 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 226800, while the sum is 43.

The spelling of 16521570349 in words is "sixteen billion, five hundred twenty-one million, five hundred seventy thousand, three hundred forty-nine".