1221504 has 32 divisors (see below), whose sum is σ = 3245640. Its totient is φ = 407040.

The previous prime is 1221503. The next prime is 1221523. The reversal of 1221504 is 4051221.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1207 + ... + 1974.

2^1221504 is an apocalyptic number.

It is an amenable number.

1221504 is an abundant number, since it is smaller than the sum of its proper divisors (2024136).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221504 is an equidigital number, since it uses as much as digits as its factorization.

1221504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3198 (or 3186 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 1221504 is about 1105.2167208290. The cubic root of 1221504 is about 106.8968639650.

Adding to 1221504 its reverse (4051221), we get a palindrome (5272725).

The spelling of 1221504 in words is "one million, two hundred twenty-one thousand, five hundred four".