305881920 has 140 divisors (see below), whose sum is σ = 1088168004. Its totient is φ = 81561600.

The previous prime is 305881909. The next prime is 305881949. The reversal of 305881920 is 29188503.

It can be written as a sum of positive squares in 2 ways, for example, as 136048896 + 169833024 = 11664^2 + 13032^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 12.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 20020 + ... + 31820.

Almost surely, 2^305881920 is an apocalyptic number.

305881920 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 305881920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (544084002).

305881920 is an abundant number, since it is smaller than the sum of its proper divisors (782286084).

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

305881920 is a wasteful number, since it uses less digits than its factorization.

305881920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11830 (or 11811 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 305881920 is about 17489.4802667203. The cubic root of 305881920 is about 673.7797212104.

The spelling of 305881920 in words is "three hundred five million, eight hundred eighty-one thousand, nine hundred twenty".