1998974138 has 32 divisors (see below), whose sum is σ = 3639302784. Its totient is φ = 803884032.

The previous prime is 1998974113. The next prime is 1998974143. The reversal of 1998974138 is 8314798991.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67745 + ... + 92667.

It is an arithmetic number, because the mean of its divisors is an integer number (113728212).

Almost surely, 2^1998974138 is an apocalyptic number.

1998974138 is a deficient number, since it is larger than the sum of its proper divisors (1640328646).

1998974138 is a wasteful number, since it uses less digits than its factorization.

1998974138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25286.

The product of its digits is 3919104, while the sum is 59.

The square root of 1998974138 is about 44709.8885930171. Note that the first 3 decimals coincide. The cubic root of 1998974138 is about 1259.7055955316.

The spelling of 1998974138 in words is "one billion, nine hundred ninety-eight million, nine hundred seventy-four thousand, one hundred thirty-eight".