3638639 has 2 divisors, whose sum is σ = 3638640. Its totient is φ = 3638638.

The previous prime is 3638573. The next prime is 3638641. The reversal of 3638639 is 9368363.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3638639 is a prime.

It is a super-3 number, since 3×3638639³ (a number of 21 digits) contains 333 as substring.

It is a Sophie Germain prime.

Together with 3638641, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3638699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1819319 + 1819320.

It is an arithmetic number, because the mean of its divisors is an integer number (1819320).

Almost surely, 2^3638639 is an apocalyptic number.

3638639 is a deficient number, since it is larger than the sum of its proper divisors (1).

3638639 is an equidigital number, since it uses as much as digits as its factorization.

3638639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 38.

The square root of 3638639 is about 1907.5216905713. The cubic root of 3638639 is about 153.8082591475.

The spelling of 3638639 in words is "three million, six hundred thirty-eight thousand, six hundred thirty-nine".