820407 has 12 divisors (see below), whose sum is σ = 1272696. Its totient is φ = 468720.

The previous prime is 820399. The next prime is 820409. The reversal of 820407 is 704028.

It is a happy number.

820407 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 820407 - 2³ = 820399 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2644 + ... + 2937.

It is an arithmetic number, because the mean of its divisors is an integer number (106058).

2⁸²⁰⁴⁰⁷ is an apocalyptic number.

820407 is a deficient number, since it is larger than the sum of its proper divisors (452289).

820407 is a wasteful number, since it uses less digits than its factorization.

820407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5598 (or 5591 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 820407 is about 905.7632140907. The cubic root of 820407 is about 93.6144993610.

The spelling of 820407 in words is "eight hundred twenty thousand, four hundred seven".