1638949 has 8 divisors (see below), whose sum is σ = 1779680. Its totient is φ = 1500336.

The previous prime is 1638947. The next prime is 1638977. The reversal of 1638949 is 9498361.

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 1638949 - 2¹ = 1638947 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1354 + ... + 2260.

It is an arithmetic number, because the mean of its divisors is an integer number (222460).

2^1638949 is an apocalyptic number.

It is an amenable number.

1638949 is a deficient number, since it is larger than the sum of its proper divisors (140731).

1638949 is a wasteful number, since it uses less digits than its factorization.

1638949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1059.

The product of its digits is 46656, while the sum is 40.

The square root of 1638949 is about 1280.2144351631. The cubic root of 1638949 is about 117.9021740205.

The spelling of 1638949 in words is "one million, six hundred thirty-eight thousand, nine hundred forty-nine".