638796911 has 2 divisors, whose sum is σ = 638796912. Its totient is φ = 638796910.

The previous prime is 638796901. The next prime is 638796931. The reversal of 638796911 is 119697836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638796911 - 2¹⁰ = 638795887 is a prime.

It is a super-2 number, since 2×638796911² = 816122987006283842, which contains 22 as substring.

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 638796911.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638796901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319398455 + 319398456.

It is an arithmetic number, because the mean of its divisors is an integer number (319398456).

Almost surely, 2^638796911 is an apocalyptic number.

638796911 is a deficient number, since it is larger than the sum of its proper divisors (1).

638796911 is an equidigital number, since it uses as much as digits as its factorization.

638796911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 50.

The square root of 638796911 is about 25274.4319619650. The cubic root of 638796911 is about 861.2335421522.

The spelling of 638796911 in words is "six hundred thirty-eight million, seven hundred ninety-six thousand, nine hundred eleven".