1387439842 has 4 divisors (see below), whose sum is σ = 2081159766. Its totient is φ = 693719920.

The previous prime is 1387439839. The next prime is 1387439857. The reversal of 1387439842 is 2489347831.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1377077881 + 10361961 = 37109^2 + 3219^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 346859959 + ... + 346859962.

Almost surely, 2^1387439842 is an apocalyptic number.

1387439842 is a deficient number, since it is larger than the sum of its proper divisors (693719924).

1387439842 is an equidigital number, since it uses as much as digits as its factorization.

1387439842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 693719923.

The product of its digits is 1161216, while the sum is 49.

The square root of 1387439842 is about 37248.3535475060. The cubic root of 1387439842 is about 1115.3334325578. Note that the first 3 decimals are identical.

The spelling of 1387439842 in words is "one billion, three hundred eighty-seven million, four hundred thirty-nine thousand, eight hundred forty-two".