20638349 has 2 divisors, whose sum is σ = 20638350. Its totient is φ = 20638348.

The previous prime is 20638339. The next prime is 20638363. The reversal of 20638349 is 94383602.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14478025 + 6160324 = 3805^2 + 2482^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20638349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20638309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10319174 + 10319175.

It is an arithmetic number, because the mean of its divisors is an integer number (10319175).

Almost surely, 2^20638349 is an apocalyptic number.

It is an amenable number.

20638349 is a deficient number, since it is larger than the sum of its proper divisors (1).

20638349 is an equidigital number, since it uses as much as digits as its factorization.

20638349 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 20638349 is about 4542.9449699507. The cubic root of 20638349 is about 274.2994798580.

The spelling of 20638349 in words is "twenty million, six hundred thirty-eight thousand, three hundred forty-nine".