281817940 has 24 divisors (see below), whose sum is σ = 612226440. Its totient is φ = 108839808.

The previous prime is 281817923. The next prime is 281817941. The reversal of 281817940 is 49718182.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 78641424 + 203176516 = 8868^2 + 14254^2 .

It is a junction number, because it is equal to n+sod(n) for n = 281817893 and 281817902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (281817941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 242367 + ... + 243526.

It is an arithmetic number, because the mean of its divisors is an integer number (25509435).

Almost surely, 2^281817940 is an apocalyptic number.

281817940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

281817940 is an abundant number, since it is smaller than the sum of its proper divisors (330408500).

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

281817940 is a wasteful number, since it uses less digits than its factorization.

281817940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 485931 (or 485929 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 40.

The square root of 281817940 is about 16787.4339909350. The cubic root of 281817940 is about 655.6260665110.

The spelling of 281817940 in words is "two hundred eighty-one million, eight hundred seventeen thousand, nine hundred forty".