636211397 has 2 divisors, whose sum is σ = 636211398. Its totient is φ = 636211396.

The previous prime is 636211313. The next prime is 636211421. The reversal of 636211397 is 793112636.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 542004961 + 94206436 = 23281^2 + 9706^2 .

It is a cyclic number.

It is not a de Polignac number, because 636211397 - 2¹⁴ = 636195013 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 636211397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (636211307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318105698 + 318105699.

It is an arithmetic number, because the mean of its divisors is an integer number (318105699).

Almost surely, 2^636211397 is an apocalyptic number.

It is an amenable number.

636211397 is a deficient number, since it is larger than the sum of its proper divisors (1).

636211397 is an equidigital number, since it uses as much as digits as its factorization.

636211397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 38.

The square root of 636211397 is about 25223.2312957718. The cubic root of 636211397 is about 860.0700308034.

The spelling of 636211397 in words is "six hundred thirty-six million, two hundred eleven thousand, three hundred ninety-seven".