636973397 has 2 divisors, whose sum is σ = 636973398. Its totient is φ = 636973396.

The previous prime is 636973369. The next prime is 636973427. The reversal of 636973397 is 793379636.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 430936081 + 206037316 = 20759^2 + 14354^2 .

It is a cyclic number.

It is not a de Polignac number, because 636973397 - 2⁶ = 636973333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636973097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318486698 + 318486699.

It is an arithmetic number, because the mean of its divisors is an integer number (318486699).

Almost surely, 2^636973397 is an apocalyptic number.

It is an amenable number.

636973397 is a deficient number, since it is larger than the sum of its proper divisors (1).

636973397 is an equidigital number, since it uses as much as digits as its factorization.

636973397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3857868, while the sum is 53.

The square root of 636973397 is about 25238.3318981267. The cubic root of 636973397 is about 860.4132667625.

The spelling of 636973397 in words is "six hundred thirty-six million, nine hundred seventy-three thousand, three hundred ninety-seven".