1981233956 has 12 divisors (see below), whose sum is σ = 3733864092. Its totient is φ = 914415648.

The previous prime is 1981233953. The next prime is 1981233959. The reversal of 1981233956 is 6593321891.

It is an interprime number because it is at equal distance from previous prime (1981233953) and next prime (1981233959).

It can be written as a sum of positive squares in 2 ways, for example, as 1032593956 + 948640000 = 32134^2 + 30800^2 .

It is a super-3 number, since 3×1981233956³ (a number of 29 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1981233956.

It is not an unprimeable number, because it can be changed into a prime (1981233953) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19050275 + ... + 19050378.

It is an arithmetic number, because the mean of its divisors is an integer number (311155341).

Almost surely, 2^1981233956 is an apocalyptic number.

It is an amenable number.

1981233956 is a deficient number, since it is larger than the sum of its proper divisors (1752630136).

1981233956 is a wasteful number, since it uses less digits than its factorization.

1981233956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38100670 (or 38100668 counting only the distinct ones).

The product of its digits is 349920, while the sum is 47.

The square root of 1981233956 is about 44511.0543123840. The cubic root of 1981233956 is about 1255.9680379509.

The spelling of 1981233956 in words is "one billion, nine hundred eighty-one million, two hundred thirty-three thousand, nine hundred fifty-six".