1981363808 has 12 divisors (see below), whose sum is σ = 3900810060. Its totient is φ = 990681888.

The previous prime is 1981363793. The next prime is 1981363817. The reversal of 1981363808 is 8083631891.

It is a happy number.

It is a super-3 number, since 3×1981363808³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30958778 + ... + 30958841.

It is an arithmetic number, because the mean of its divisors is an integer number (325067505).

Almost surely, 2^1981363808 is an apocalyptic number.

It is an amenable number.

1981363808 is a deficient number, since it is larger than the sum of its proper divisors (1919446252).

1981363808 is an equidigital number, since it uses as much as digits as its factorization.

1981363808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61917629 (or 61917621 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 47.

The square root of 1981363808 is about 44512.5129373753. The cubic root of 1981363808 is about 1255.9954764736.

The spelling of 1981363808 in words is "one billion, nine hundred eighty-one million, three hundred sixty-three thousand, eight hundred eight".