780001 has 4 divisors (see below), whose sum is σ = 794772. Its totient is φ = 765232.

The previous prime is 779993. The next prime is 780029. The reversal of 780001 is 100087.

780001 = 624² + 625².

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 100087 = 13 ⋅7699.

It can be written as a sum of positive squares in 2 ways, for example, as 389376 + 390625 = 624^2 + 625^2 .

It is a cyclic number.

It is not a de Polignac number, because 780001 - 2³ = 779993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (780041) 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, 7306 + ... + 7411.

It is an arithmetic number, because the mean of its divisors is an integer number (198693).

2⁷⁸⁰⁰⁰¹ is an apocalyptic number.

780001 is the 625-th centered square number.

It is an amenable number.

780001 is a deficient number, since it is larger than the sum of its proper divisors (14771).

780001 is a wasteful number, since it uses less digits than its factorization.

780001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14770.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 780001 is about 883.1766527711. The cubic root of 780001 is about 92.0516801635.

Adding to 780001 its reverse (100087), we get a palindrome (880088).

It can be divided in two parts, 7 and 80001, that added together give a palindrome (80008).

The spelling of 780001 in words is "seven hundred eighty thousand, one".