1981800826 has 8 divisors (see below), whose sum is σ = 2977927380. Its totient is φ = 989158368.

The previous prime is 1981800817. The next prime is 1981800851. The reversal of 1981800826 is 6280081891.

It can be written as a sum of positive squares in 2 ways, for example, as 1953551601 + 28249225 = 44199^2 + 5315^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 869601 + ... + 871876.

Almost surely, 2^1981800826 is an apocalyptic number.

1981800826 is a deficient number, since it is larger than the sum of its proper divisors (996126554).

1981800826 is a wasteful number, since it uses less digits than its factorization.

1981800826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1742048.

The product of its (nonzero) digits is 55296, while the sum is 43.

The square root of 1981800826 is about 44517.4216009867. The cubic root of 1981800826 is about 1256.0878122474.

The spelling of 1981800826 in words is "one billion, nine hundred eighty-one million, eight hundred thousand, eight hundred twenty-six".