1020409 has 8 divisors (see below), whose sum is σ = 1120392. Its totient is φ = 923520.

The previous prime is 1020407. The next prime is 1020413. The reversal of 1020409 is 9040201.

It can be written as a sum of positive squares in 4 ways, for example, as 75625 + 944784 = 275^2 + 972^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1020409 - 2¹ = 1020407 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1020392 and 1020401.

It is not an unprimeable number, because it can be changed into a prime (1020401) 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 7 ways as a sum of consecutive naturals, for example, 52 + ... + 1429.

It is an arithmetic number, because the mean of its divisors is an integer number (140049).

2^1020409 is an apocalyptic number.

It is an amenable number.

1020409 is a deficient number, since it is larger than the sum of its proper divisors (99983).

1020409 is a wasteful number, since it uses less digits than its factorization.

1020409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1547.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1020409 is about 1010.1529587147. The cubic root of 1020409 is about 100.6757236904.

The spelling of 1020409 in words is "one million, twenty thousand, four hundred nine".