1221043404 has 48 divisors (see below), whose sum is σ = 3257827328. Its totient is φ = 348686208.

The previous prime is 1221043391. The next prime is 1221043433. The reversal of 1221043404 is 4043401221.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 298944 + ... + 303000.

Almost surely, 2^1221043404 is an apocalyptic number.

1221043404 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1221043404 is an abundant number, since it is smaller than the sum of its proper divisors (2036783924).

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

1221043404 is a wasteful number, since it uses less digits than its factorization.

1221043404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7654 (or 7652 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 1221043404 is about 34943.4314857600. The cubic root of 1221043404 is about 1068.8342630735.

Adding to 1221043404 its reverse (4043401221), we get a palindrome (5264444625).

The spelling of 1221043404 in words is "one billion, two hundred twenty-one million, forty-three thousand, four hundred four".