1981436900 has 36 divisors (see below), whose sum is σ = 4307002980. Its totient is φ = 791232000.

The previous prime is 1981436851. The next prime is 1981436923. The reversal of 1981436900 is 96341891.

It can be written as a sum of positive squares in 6 ways, for example, as 652864 + 1980784036 = 808^2 + 44506^2 .

It is a super-3 number, since 3×1981436900³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43616 + ... + 76584.

Almost surely, 2^1981436900 is an apocalyptic number.

1981436900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1981436900 is an abundant number, since it is smaller than the sum of its proper divisors (2325566080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1981436900 is a wasteful number, since it uses less digits than its factorization.

1981436900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33584 (or 33577 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 1981436900 is about 44513.3339573661. Note that the first 3 decimals coincide. The cubic root of 1981436900 is about 1256.0109207335.

The spelling of 1981436900 in words is "one billion, nine hundred eighty-one million, four hundred thirty-six thousand, nine hundred".