1981680338 has 16 divisors (see below), whose sum is σ = 3287173536. Its totient is φ = 888423840.

The previous prime is 1981680329. The next prime is 1981680367. The reversal of 1981680338 is 8330861891.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1981680292 and 1981680301.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 615356 + ... + 618567.

It is an arithmetic number, because the mean of its divisors is an integer number (205448346).

Almost surely, 2^1981680338 is an apocalyptic number.

1981680338 is a deficient number, since it is larger than the sum of its proper divisors (1305493198).

1981680338 is a wasteful number, since it uses less digits than its factorization.

1981680338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1234009.

The product of its (nonzero) digits is 248832, while the sum is 47.

The square root of 1981680338 is about 44516.0683124644. The cubic root of 1981680338 is about 1256.0623561784.

The spelling of 1981680338 in words is "one billion, nine hundred eighty-one million, six hundred eighty thousand, three hundred thirty-eight".