18838649 has 2 divisors, whose sum is σ = 18838650. Its totient is φ = 18838648.

The previous prime is 18838613. The next prime is 18838657. The reversal of 18838649 is 94683881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12924025 + 5914624 = 3595^2 + 2432^2 .

It is a cyclic number.

It is not a de Polignac number, because 18838649 - 2¹² = 18834553 is a prime.

It is a super-2 number, since 2×18838649² = 709789392290402, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18838249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9419324 + 9419325.

It is an arithmetic number, because the mean of its divisors is an integer number (9419325).

Almost surely, 2^18838649 is an apocalyptic number.

It is an amenable number.

18838649 is a deficient number, since it is larger than the sum of its proper divisors (1).

18838649 is an equidigital number, since it uses as much as digits as its factorization.

18838649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 331776, while the sum is 47.

The square root of 18838649 is about 4340.3512530670. The cubic root of 18838649 is about 266.0826669401.

The spelling of 18838649 in words is "eighteen million, eight hundred thirty-eight thousand, six hundred forty-nine".