1981577900 has 18 divisors (see below), whose sum is σ = 4300024260. Its totient is φ = 792631120.

The previous prime is 1981577881. The next prime is 1981577911. The reversal of 1981577900 is 97751891.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 9907790 + ... + 9907989.

Almost surely, 2^1981577900 is an apocalyptic number.

1981577900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1981577900 is an abundant number, since it is smaller than the sum of its proper divisors (2318446360).

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

1981577900 is a wasteful number, since it uses less digits than its factorization.

1981577900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19815793 (or 19815786 counting only the distinct ones).

The product of its (nonzero) digits is 158760, while the sum is 47.

The square root of 1981577900 is about 44514.9177242865. The cubic root of 1981577900 is about 1256.0407128066.

The spelling of 1981577900 in words is "one billion, nine hundred eighty-one million, five hundred seventy-seven thousand, nine hundred".