1221145404 has 24 divisors (see below), whose sum is σ = 2855962368. Its totient is φ = 406102320.

The previous prime is 1221145403. The next prime is 1221145469. The reversal of 1221145404 is 4045411221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221145403) 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, 112882 + ... + 123225.

It is an arithmetic number, because the mean of its divisors is an integer number (118998432).

Almost surely, 2^1221145404 is an apocalyptic number.

It is an amenable number.

1221145404 is an abundant number, since it is smaller than the sum of its proper divisors (1634816964).

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

1221145404 is a wasteful number, since it uses less digits than its factorization.

1221145404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236545 (or 236543 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 1221145404 is about 34944.8909570484. The cubic root of 1221145404 is about 1068.8640239755.

Adding to 1221145404 its reverse (4045411221), we get a palindrome (5266556625).

The spelling of 1221145404 in words is "one billion, two hundred twenty-one million, one hundred forty-five thousand, four hundred four".