781264 has 40 divisors (see below), whose sum is σ = 1732032. Its totient is φ = 337920.

The previous prime is 781247. The next prime is 781271. The reversal of 781264 is 462187.

It is a super-2 number, since 2×781264² = 1220746875392, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3952 + ... + 4144.

781264 is a Friedman number, since it can be written as 2*(7+(6-1^4)^8), using all its digits and the basic arithmetic operations.

2⁷⁸¹²⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 781264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (866016).

781264 is an abundant number, since it is smaller than the sum of its proper divisors (950768).

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

781264 is a wasteful number, since it uses less digits than its factorization.

781264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235 (or 229 counting only the distinct ones).

The product of its digits is 2688, while the sum is 28.

The square root of 781264 is about 883.8913960437. The cubic root of 781264 is about 92.1013376114.

The spelling of 781264 in words is "seven hundred eighty-one thousand, two hundred sixty-four".