1242005 has 4 divisors (see below), whose sum is σ = 1490412. Its totient is φ = 993600.

The previous prime is 1242001. The next prime is 1242029. The reversal of 1242005 is 5002421.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 306916 + 935089 = 554^2 + 967^2 .

It is not a de Polignac number, because 1242005 - 2² = 1242001 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242001) 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, 124196 + ... + 124205.

It is an arithmetic number, because the mean of its divisors is an integer number (372603).

2^1242005 is an apocalyptic number.

It is an amenable number.

1242005 is a deficient number, since it is larger than the sum of its proper divisors (248407).

1242005 is an equidigital number, since it uses as much as digits as its factorization.

1242005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248406.

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 1242005 is about 1114.4527805161. The cubic root of 1242005 is about 107.4915803754.

Adding to 1242005 its reverse (5002421), we get a palindrome (6244426).

The spelling of 1242005 in words is "one million, two hundred forty-two thousand, five".