16939691 has 2 divisors, whose sum is σ = 16939692. Its totient is φ = 16939690.

The previous prime is 16939687. The next prime is 16939709. The reversal of 16939691 is 19693961.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16939691 - 2² = 16939687 is a prime.

It is a plaindrome in base 9.

It is not a weakly prime, because it can be changed into another prime (16939631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8469845 + 8469846.

It is an arithmetic number, because the mean of its divisors is an integer number (8469846).

Almost surely, 2^16939691 is an apocalyptic number.

16939691 is a deficient number, since it is larger than the sum of its proper divisors (1).

16939691 is an equidigital number, since it uses as much as digits as its factorization.

16939691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 78732, while the sum is 44.

The square root of 16939691 is about 4115.7855872239. The cubic root of 16939691 is about 256.8237371830.

The spelling of 16939691 in words is "sixteen million, nine hundred thirty-nine thousand, six hundred ninety-one".