1986891538 has 16 divisors (see below), whose sum is σ = 2990249856. Its totient is φ = 990148320.

The previous prime is 1986891479. The next prime is 1986891539. The reversal of 1986891538 is 8351986891.

It is not an unprimeable number, because it can be changed into a prime (1986891539) by changing a digit.

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, 1037670 + ... + 1039582.

It is an arithmetic number, because the mean of its divisors is an integer number (186890616).

Almost surely, 2^1986891538 is an apocalyptic number.

1986891538 is a deficient number, since it is larger than the sum of its proper divisors (1003358318).

1986891538 is a wasteful number, since it uses less digits than its factorization.

1986891538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3369.

The product of its digits is 3732480, while the sum is 58.

The square root of 1986891538 is about 44574.5615570137. The cubic root of 1986891538 is about 1257.1624096317.

The spelling of 1986891538 in words is "one billion, nine hundred eighty-six million, eight hundred ninety-one thousand, five hundred thirty-eight".