1638933049 has 8 divisors (see below), whose sum is σ = 1783202120. Its totient is φ = 1497263616.

The previous prime is 1638933031. The next prime is 1638933083. The reversal of 1638933049 is 9403398361.

It can be written as a sum of positive squares in 4 ways, for example, as 28355625 + 1610577424 = 5325^2 + 40132^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1638933049 - 2²³ = 1630544441 is a prime.

It is a super-2 number, since 2×1638933049² = 5372203078208872802, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1638934049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 648594 + ... + 651115.

It is an arithmetic number, because the mean of its divisors is an integer number (222900265).

Almost surely, 2^1638933049 is an apocalyptic number.

It is an amenable number.

1638933049 is a deficient number, since it is larger than the sum of its proper divisors (144269071).

1638933049 is a wasteful number, since it uses less digits than its factorization.

1638933049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1299819.

The product of its (nonzero) digits is 419904, while the sum is 46.

The square root of 1638933049 is about 40483.7380808640. The cubic root of 1638933049 is about 1179.0179152665.

The spelling of 1638933049 in words is "one billion, six hundred thirty-eight million, nine hundred thirty-three thousand, forty-nine".