1981640033 has 8 divisors (see below), whose sum is σ = 2012040000. Its totient is φ = 1951309360.

The previous prime is 1981640009. The next prime is 1981640047. The reversal of 1981640033 is 3300461891.

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

It is a cyclic number.

It is not a de Polignac number, because 1981640033 - 2¹⁸ = 1981377889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1981639975 and 1981640002.

It is not an unprimeable number, because it can be changed into a prime (1981640053) 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, 41843 + ... + 75591.

It is an arithmetic number, because the mean of its divisors is an integer number (251505000).

Almost surely, 2^1981640033 is an apocalyptic number.

It is an amenable number.

1981640033 is a deficient number, since it is larger than the sum of its proper divisors (30399967).

1981640033 is an equidigital number, since it uses as much as digits as its factorization.

1981640033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34647.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 1981640033 is about 44515.6156084581. The cubic root of 1981640033 is about 1256.0538405203.

The spelling of 1981640033 in words is "one billion, nine hundred eighty-one million, six hundred forty thousand, thirty-three".