1987139378 has 16 divisors (see below), whose sum is σ = 3410817984. Its totient is φ = 850557840.

The previous prime is 1987139321. The next prime is 1987139389. The reversal of 1987139378 is 8739317891.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77888 + ... + 100203.

It is an arithmetic number, because the mean of its divisors is an integer number (213176124).

Almost surely, 2^1987139378 is an apocalyptic number.

1987139378 is a deficient number, since it is larger than the sum of its proper divisors (1423678606).

1987139378 is a wasteful number, since it uses less digits than its factorization.

1987139378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178897.

The product of its digits is 2286144, while the sum is 56.

The square root of 1987139378 is about 44577.3415313206. The cubic root of 1987139378 is about 1257.2146792484.

The spelling of 1987139378 in words is "one billion, nine hundred eighty-seven million, one hundred thirty-nine thousand, three hundred seventy-eight".