16521091 has 2 divisors, whose sum is σ = 16521092. Its totient is φ = 16521090.

The previous prime is 16521053. The next prime is 16521101. The reversal of 16521091 is 19012561.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16521091 - 2¹⁵ = 16488323 is a prime.

It is equal to p_1062448 and since 16521091 and 1062448 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (16521031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8260545 + 8260546.

It is an arithmetic number, because the mean of its divisors is an integer number (8260546).

Almost surely, 2^16521091 is an apocalyptic number.

16521091 is a deficient number, since it is larger than the sum of its proper divisors (1).

16521091 is an equidigital number, since it uses as much as digits as its factorization.

16521091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 540, while the sum is 25.

The square root of 16521091 is about 4064.6144958655. The cubic root of 16521091 is about 254.6905948738.

The spelling of 16521091 in words is "sixteen million, five hundred twenty-one thousand, ninety-one".