281820825 has 144 divisors (see below), whose sum is σ = 625584960. Its totient is φ = 119232000.

The previous prime is 281820779. The next prime is 281820841. The reversal of 281820825 is 528028182.

It is a happy number.

It is not a de Polignac number, because 281820825 - 2⁷ = 281820697 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 281820825.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 611095 + ... + 611555.

It is an arithmetic number, because the mean of its divisors is an integer number (4344340).

Almost surely, 2^281820825 is an apocalyptic number.

281820825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

281820825 is an abundant number, since it is smaller than the sum of its proper divisors (343764135).

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

281820825 is a wasteful number, since it uses less digits than its factorization.

281820825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520 (or 512 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 36.

The square root of 281820825 is about 16787.5199180820. The cubic root of 281820825 is about 655.6283037411.

The spelling of 281820825 in words is "two hundred eighty-one million, eight hundred twenty thousand, eight hundred twenty-five".