646194691 has 2 divisors, whose sum is σ = 646194692. Its totient is φ = 646194690.

The previous prime is 646194671. The next prime is 646194707. The reversal of 646194691 is 196491646.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 646194691 - 2¹⁷ = 646063619 is a prime.

It is not a weakly prime, because it can be changed into another prime (646194631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323097345 + 323097346.

It is an arithmetic number, because the mean of its divisors is an integer number (323097346).

Almost surely, 2^646194691 is an apocalyptic number.

646194691 is a deficient number, since it is larger than the sum of its proper divisors (1).

646194691 is an equidigital number, since it uses as much as digits as its factorization.

646194691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 279936, while the sum is 46.

The square root of 646194691 is about 25420.3597732211. The cubic root of 646194691 is about 864.5453817435.

The spelling of 646194691 in words is "six hundred forty-six million, one hundred ninety-four thousand, six hundred ninety-one".