638279949 has 8 divisors (see below), whose sum is σ = 851224480. Its totient is φ = 425427696.

The previous prime is 638279927. The next prime is 638279951. The reversal of 638279949 is 949972836.

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

It is not a de Polignac number, because 638279949 - 2¹³ = 638271757 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638279249) 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, 4879 + ... + 36060.

It is an arithmetic number, because the mean of its divisors is an integer number (106403060).

Almost surely, 2^638279949 is an apocalyptic number.

It is an amenable number.

638279949 is a deficient number, since it is larger than the sum of its proper divisors (212944531).

638279949 is a wasteful number, since it uses less digits than its factorization.

638279949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46139.

The product of its digits is 5878656, while the sum is 57.

The square root of 638279949 is about 25264.2029163795. The cubic root of 638279949 is about 861.0011546939.

The spelling of 638279949 in words is "six hundred thirty-eight million, two hundred seventy-nine thousand, nine hundred forty-nine".