1221031404 has 18 divisors (see below), whose sum is σ = 3086496140. Its totient is φ = 407010456.

The previous prime is 1221031403. The next prime is 1221031423. The reversal of 1221031404 is 4041301221.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×1221031404² = 2981835379108422432, which contains 22 as substring.

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 (1221031403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16958734 + ... + 16958805.

Almost surely, 2^1221031404 is an apocalyptic number.

It is an amenable number.

1221031404 is an abundant number, since it is smaller than the sum of its proper divisors (1865464736).

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

1221031404 is a wasteful number, since it uses less digits than its factorization.

1221031404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33917549 (or 33917544 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 1221031404 is about 34943.2597792478. The cubic root of 1221031404 is about 1068.8307616819.

Adding to 1221031404 its reverse (4041301221), we get a palindrome (5262332625).

The spelling of 1221031404 in words is "one billion, two hundred twenty-one million, thirty-one thousand, four hundred four".