16209691 has 2 divisors, whose sum is σ = 16209692. Its totient is φ = 16209690.

The previous prime is 16209643. The next prime is 16209701. The reversal of 16209691 is 19690261.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16209691 - 2⁷ = 16209563 is a prime.

It is not a weakly prime, because it can be changed into another prime (16207691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8104845 + 8104846.

It is an arithmetic number, because the mean of its divisors is an integer number (8104846).

Almost surely, 2^16209691 is an apocalyptic number.

16209691 is a deficient number, since it is larger than the sum of its proper divisors (1).

16209691 is an equidigital number, since it uses as much as digits as its factorization.

16209691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 16209691 is about 4026.1260536650. The cubic root of 16209691 is about 253.0802445080.

It can be divided in two parts, 16209 and 691, that added together give a square (16900 = 130²).

The spelling of 16209691 in words is "sixteen million, two hundred nine thousand, six hundred ninety-one".