1638486949 has 8 divisors (see below), whose sum is σ = 1865155392. Its totient is φ = 1424771040.

The previous prime is 1638486841. The next prime is 1638486973. The reversal of 1638486949 is 9496848361.

It is a happy number.

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

It is not a de Polignac number, because 1638486949 - 2⁷ = 1638486821 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1638486893 and 1638486902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638486349) 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, 3237864 + ... + 3238369.

It is an arithmetic number, because the mean of its divisors is an integer number (233144424).

Almost surely, 2^1638486949 is an apocalyptic number.

It is an amenable number.

1638486949 is a deficient number, since it is larger than the sum of its proper divisors (226668443).

1638486949 is a wasteful number, since it uses less digits than its factorization.

1638486949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6476267.

The product of its digits is 8957952, while the sum is 58.

The square root of 1638486949 is about 40478.2280862194. The cubic root of 1638486949 is about 1178.9109335485.

The spelling of 1638486949 in words is "one billion, six hundred thirty-eight million, four hundred eighty-six thousand, nine hundred forty-nine".