1642405 has 4 divisors (see below), whose sum is σ = 1970892. Its totient is φ = 1313920.

The previous prime is 1642397. The next prime is 1642423. The reversal of 1642405 is 5042461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5042461 = 199 ⋅25339.

It can be written as a sum of positive squares in 2 ways, for example, as 638401 + 1004004 = 799^2 + 1002^2 .

It is not a de Polignac number, because 1642405 - 2³ = 1642397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164236 + ... + 164245.

It is an arithmetic number, because the mean of its divisors is an integer number (492723).

2^1642405 is an apocalyptic number.

It is an amenable number.

1642405 is a deficient number, since it is larger than the sum of its proper divisors (328487).

1642405 is an equidigital number, since it uses as much as digits as its factorization.

1642405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328486.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 1642405 is about 1281.5634982317. The cubic root of 1642405 is about 117.9849880357.

Adding to 1642405 its reverse (5042461), we get a palindrome (6684866).

The spelling of 1642405 in words is "one million, six hundred forty-two thousand, four hundred five".