1240405 has 8 divisors (see below), whose sum is σ = 1576152. Its totient is φ = 933888.

The previous prime is 1240399. The next prime is 1240423. The reversal of 1240405 is 5040421.

It can be written as a sum of positive squares in 4 ways, for example, as 61009 + 1179396 = 247^2 + 1086^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1240405 - 2⁹ = 1239893 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7212 + ... + 7381.

It is an arithmetic number, because the mean of its divisors is an integer number (197019).

2^1240405 is an apocalyptic number.

It is an amenable number.

1240405 is a deficient number, since it is larger than the sum of its proper divisors (335747).

1240405 is a wasteful number, since it uses less digits than its factorization.

1240405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14615.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 1240405 is about 1113.7347080881. The cubic root of 1240405 is about 107.4454022374.

Adding to 1240405 its sum of digits (16), we get a palindrome (1240421).

Adding to 1240405 its reverse (5040421), we get a palindrome (6280826).

The spelling of 1240405 in words is "one million, two hundred forty thousand, four hundred five".