781404 has 24 divisors (see below), whose sum is σ = 1963920. Its totient is φ = 240384.

The previous prime is 781399. The next prime is 781409. The reversal of 781404 is 404187.

It is an interprime number because it is at equal distance from previous prime (781399) and next prime (781409).

It is a super-2 number, since 2×781404² = 1221184422432, which contains 22 as substring.

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 781404.

It is not an unprimeable number, because it can be changed into a prime (781409) by changing a digit.

781404 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2349 + ... + 2660.

It is an arithmetic number, because the mean of its divisors is an integer number (81830).

2⁷⁸¹⁴⁰⁴ is an apocalyptic number.

It is an amenable number.

781404 is an abundant number, since it is smaller than the sum of its proper divisors (1182516).

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

781404 is a wasteful number, since it uses less digits than its factorization.

781404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5029 (or 5027 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 781404 is about 883.9705877460. The cubic root of 781404 is about 92.1068387042.

The spelling of 781404 in words is "seven hundred eighty-one thousand, four hundred four".