284640321 has 32 divisors (see below), whose sum is σ = 444791808. Its totient is φ = 158558400.

The previous prime is 284640313. The next prime is 284640361. The reversal of 284640321 is 123046482.

It is not a de Polignac number, because 284640321 - 2³ = 284640313 is a prime.

It is a super-2 number, since 2×284640321² = 162040224677966082, which contains 22 as substring.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (284640361) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 141106 + ... + 143108.

It is an arithmetic number, because the mean of its divisors is an integer number (13899744).

Almost surely, 2^284640321 is an apocalyptic number.

284640321 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

284640321 is a deficient number, since it is larger than the sum of its proper divisors (160151487).

284640321 is a wasteful number, since it uses less digits than its factorization.

284640321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2181.

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 284640321 is about 16871.2868803776. The cubic root of 284640321 is about 657.8074788682.

The spelling of 284640321 in words is "two hundred eighty-four million, six hundred forty thousand, three hundred twenty-one".