1221044004 has 24 divisors (see below), whose sum is σ = 3165669920. Its totient is φ = 407014632.

The previous prime is 1221044003. The next prime is 1221044009. The reversal of 1221044004 is 4004401221.

1221044004 is a `hidden beast` number, since 1 + 221 + 0 + 440 + 0 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (1221044003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5652874 + ... + 5653089.

Almost surely, 2^1221044004 is an apocalyptic number.

It is an amenable number.

1221044004 is an abundant number, since it is smaller than the sum of its proper divisors (1944625916).

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

1221044004 is a wasteful number, since it uses less digits than its factorization.

1221044004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11305976 (or 11305968 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 1221044004 is about 34943.4400710634. The cubic root of 1221044004 is about 1068.8344381425.

Adding to 1221044004 its reverse (4004401221), we get a palindrome (5225445225).

The spelling of 1221044004 in words is "one billion, two hundred twenty-one million, forty-four thousand, four".