781428 has 12 divisors (see below), whose sum is σ = 1823360. Its totient is φ = 260472.

The previous prime is 781427. The next prime is 781433. The reversal of 781428 is 824187.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×781428² = 1221259438368, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 781395 and 781404.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 781428.

It is not an unprimeable number, because it can be changed into a prime (781423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32548 + ... + 32571.

2⁷⁸¹⁴²⁸ is an apocalyptic number.

It is an amenable number.

781428 is an abundant number, since it is smaller than the sum of its proper divisors (1041932).

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

781428 is a wasteful number, since it uses less digits than its factorization.

781428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65126 (or 65124 counting only the distinct ones).

The product of its digits is 3584, while the sum is 30.

The square root of 781428 is about 883.9841627541. The cubic root of 781428 is about 92.1077816827.

The spelling of 781428 in words is "seven hundred eighty-one thousand, four hundred twenty-eight".