1981975633 has 16 divisors (see below), whose sum is σ = 2337474240. Its totient is φ = 1660824000.

The previous prime is 1981975631. The next prime is 1981975637. The reversal of 1981975633 is 3365791891.

It is a happy number.

It is not a de Polignac number, because 1981975633 - 2¹ = 1981975631 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1981975631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120418 + ... + 135883.

It is an arithmetic number, because the mean of its divisors is an integer number (146092140).

Almost surely, 2^1981975633 is an apocalyptic number.

It is an amenable number.

1981975633 is a deficient number, since it is larger than the sum of its proper divisors (355498607).

1981975633 is a wasteful number, since it uses less digits than its factorization.

1981975633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256368.

The product of its digits is 1224720, while the sum is 52.

The square root of 1981975633 is about 44519.3849126423. The cubic root of 1981975633 is about 1256.1247427138.

The spelling of 1981975633 in words is "one billion, nine hundred eighty-one million, nine hundred seventy-five thousand, six hundred thirty-three".