281628820 has 24 divisors (see below), whose sum is σ = 645186528. Its totient is φ = 102410400.

The previous prime is 281628799. The next prime is 281628821. The reversal of 281628820 is 28826182.

It is a self number, because there is not a number n which added to its sum of digits gives 281628820.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (281628821) 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, 639846 + ... + 640285.

It is an arithmetic number, because the mean of its divisors is an integer number (26882772).

Almost surely, 2^281628820 is an apocalyptic number.

281628820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

281628820 is an abundant number, since it is smaller than the sum of its proper divisors (363557708).

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

281628820 is a wasteful number, since it uses less digits than its factorization.

281628820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1280151 (or 1280149 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 37.

The square root of 281628820 is about 16781.8002609970. The cubic root of 281628820 is about 655.4793763607.

The spelling of 281628820 in words is "two hundred eighty-one million, six hundred twenty-eight thousand, eight hundred twenty".