781228 has 12 divisors (see below), whose sum is σ = 1562512. Its totient is φ = 334800.

The previous prime is 781217. The next prime is 781229. The reversal of 781228 is 822187.

781228 is an admirable number.

It is a super-2 number, since 2×781228² = 1220634375968, which contains 22 as substring.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28), and also a Moran number because the ratio is a prime number: 27901 = 781228 / (7 + 8 + 1 + 2 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 781196 and 781205.

It is not an unprimeable number, because it can be changed into a prime (781229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13923 + ... + 13978.

2⁷⁸¹²²⁸ is an apocalyptic number.

It is an amenable number.

781228 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

781228 is a wasteful number, since it uses less digits than its factorization.

781228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27912 (or 27910 counting only the distinct ones).

The product of its digits is 1792, while the sum is 28.

The square root of 781228 is about 883.8710313162. The cubic root of 781228 is about 92.0999229385.

The spelling of 781228 in words is "seven hundred eighty-one thousand, two hundred twenty-eight".