646633693 has 2 divisors, whose sum is σ = 646633694. Its totient is φ = 646633692.

The previous prime is 646633679. The next prime is 646633703. The reversal of 646633693 is 396336646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 369677529 + 276956164 = 19227^2 + 16642^2 .

It is a cyclic number.

It is not a de Polignac number, because 646633693 - 2¹³ = 646625501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646633633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323316846 + 323316847.

It is an arithmetic number, because the mean of its divisors is an integer number (323316847).

Almost surely, 2^646633693 is an apocalyptic number.

It is an amenable number.

646633693 is a deficient number, since it is larger than the sum of its proper divisors (1).

646633693 is an equidigital number, since it uses as much as digits as its factorization.

646633693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1259712, while the sum is 46.

The square root of 646633693 is about 25428.9931574178. The cubic root of 646633693 is about 864.7411180241.

The spelling of 646633693 in words is "six hundred forty-six million, six hundred thirty-three thousand, six hundred ninety-three".