1211221404 has 48 divisors (see below), whose sum is σ = 3156199200. Its totient is φ = 401683968.

The previous prime is 1211221387. The next prime is 1211221409. The reversal of 1211221404 is 4041221121.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211221409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7189 + ... + 49740.

It is an arithmetic number, because the mean of its divisors is an integer number (65754150).

Almost surely, 2^1211221404 is an apocalyptic number.

It is an amenable number.

1211221404 is an abundant number, since it is smaller than the sum of its proper divisors (1944977796).

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

1211221404 is a wasteful number, since it uses less digits than its factorization.

1211221404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57139 (or 57131 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 1211221404 is about 34802.6062817140. The cubic root of 1211221404 is about 1065.9606646309.

Adding to 1211221404 its reverse (4041221121), we get a palindrome (5252442525).

The spelling of 1211221404 in words is "one billion, two hundred eleven million, two hundred twenty-one thousand, four hundred four".