778491 has 20 divisors (see below), whose sum is σ = 1330032. Its totient is φ = 444528.

The previous prime is 778469. The next prime is 778507. The reversal of 778491 is 194877.

It is not a de Polignac number, because 778491 - 2⁷ = 778363 is a prime.

It is not an unprimeable number, because it can be changed into a prime (778091) 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 19 ways as a sum of consecutive naturals, for example, 120 + ... + 1253.

2⁷⁷⁸⁴⁹¹ is an apocalyptic number.

778491 is a deficient number, since it is larger than the sum of its proper divisors (551541).

778491 is a wasteful number, since it uses less digits than its factorization.

778491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1392 (or 1383 counting only the distinct ones).

The product of its digits is 14112, while the sum is 36.

The square root of 778491 is about 882.3213700234. The cubic root of 778491 is about 91.9922409966.

It can be divided in two parts, 7784 and 91, that added together give a triangular number (7875 = T₁₂₅).

The spelling of 778491 in words is "seven hundred seventy-eight thousand, four hundred ninety-one".