1221333431 has 16 divisors (see below), whose sum is σ = 1320948000. Its totient is φ = 1124917248.

The previous prime is 1221333413. The next prime is 1221333439. The reversal of 1221333431 is 1343331221.

It is a cyclic number.

It is not a de Polignac number, because 1221333431 - 2⁶ = 1221333367 is a prime.

It is a super-2 number, since 2×1221333431² = 2983310699356463522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221333397 and 1221333406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221333439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 403040 + ... + 406058.

It is an arithmetic number, because the mean of its divisors is an integer number (82559250).

Almost surely, 2^1221333431 is an apocalyptic number.

1221333431 is a deficient number, since it is larger than the sum of its proper divisors (99614569).

1221333431 is a wasteful number, since it uses less digits than its factorization.

1221333431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3538.

The product of its digits is 1296, while the sum is 23.

The square root of 1221333431 is about 34947.5811895473. The cubic root of 1221333431 is about 1068.9188809376.

Adding to 1221333431 its reverse (1343331221), we get a palindrome (2564664652).

The spelling of 1221333431 in words is "one billion, two hundred twenty-one million, three hundred thirty-three thousand, four hundred thirty-one".