636946997 has 2 divisors, whose sum is σ = 636946998. Its totient is φ = 636946996.

The previous prime is 636946979. The next prime is 636947029. The reversal of 636946997 is 799649636.

Together with previous prime (636946979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 458216836 + 178730161 = 21406^2 + 13369^2 .

636946997 is a truncatable prime.

It is a cyclic number.

It is not a de Polignac number, because 636946997 - 2²² = 632752693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636946907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318473498 + 318473499.

It is an arithmetic number, because the mean of its divisors is an integer number (318473499).

Almost surely, 2^636946997 is an apocalyptic number.

It is an amenable number.

636946997 is a deficient number, since it is larger than the sum of its proper divisors (1).

636946997 is an equidigital number, since it uses as much as digits as its factorization.

636946997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13226976, while the sum is 59.

The square root of 636946997 is about 25237.8088787438. The cubic root of 636946997 is about 860.4013797020.

The spelling of 636946997 in words is "six hundred thirty-six million, nine hundred forty-six thousand, nine hundred ninety-seven".