1240409 has 4 divisors (see below), whose sum is σ = 1250304. Its totient is φ = 1230516.

The previous prime is 1240399. The next prime is 1240423. The reversal of 1240409 is 9040421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1240409 - 2⁸ = 1240153 is a prime.

It is a super-2 number, since 2×1240409² = 3077228974562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1240009) 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, 4757 + ... + 5010.

It is an arithmetic number, because the mean of its divisors is an integer number (312576).

2^1240409 is an apocalyptic number.

It is an amenable number.

1240409 is a deficient number, since it is larger than the sum of its proper divisors (9895).

1240409 is an equidigital number, since it uses as much as digits as its factorization.

1240409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9894.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 1240409 is about 1113.7365038464. The cubic root of 1240409 is about 107.4455177322.

The spelling of 1240409 in words is "one million, two hundred forty thousand, four hundred nine".