1020405 has 16 divisors (see below), whose sum is σ = 1661760. Its totient is φ = 534528.

The previous prime is 1020401. The next prime is 1020407. The reversal of 1020405 is 5040201.

It is not a de Polignac number, because 1020405 - 2² = 1020401 is a prime.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 309 + ... + 1461.

It is an arithmetic number, because the mean of its divisors is an integer number (103860).

2^1020405 is an apocalyptic number.

1020405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1020405 is a deficient number, since it is larger than the sum of its proper divisors (641355).

1020405 is a wasteful number, since it uses less digits than its factorization.

1020405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1220.

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 1020405 is about 1010.1509788146. The cubic root of 1020405 is about 100.6755921407.

Adding to 1020405 its reverse (5040201), we get a palindrome (6060606).

The spelling of 1020405 in words is "one million, twenty thousand, four hundred five".