1220405 has 8 divisors (see below), whose sum is σ = 1486752. Its totient is φ = 961488.

The previous prime is 1220393. The next prime is 1220411. The reversal of 1220405 is 5040221.

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 1220405 - 2¹⁸ = 958261 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1220405.

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, 1487 + ... + 2156.

It is an arithmetic number, because the mean of its divisors is an integer number (185844).

2^1220405 is an apocalyptic number.

It is an amenable number.

1220405 is a deficient number, since it is larger than the sum of its proper divisors (266347).

1220405 is an equidigital number, since it uses as much as digits as its factorization.

1220405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3715.

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

The square root of 1220405 is about 1104.7194213917. The cubic root of 1220405 is about 106.8647956013.

Adding to 1220405 its reverse (5040221), we get a palindrome (6260626).

The spelling of 1220405 in words is "one million, two hundred twenty thousand, four hundred five".