1221426331 has 4 divisors (see below), whose sum is σ = 1222576432. Its totient is φ = 1220276232.

The previous prime is 1221426317. The next prime is 1221426337. The reversal of 1221426331 is 1336241221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221426331 - 2¹¹ = 1221424283 is a prime.

It is a super-2 number, since 2×1221426331² = 2983764564120243122, 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 = 1221426296 and 1221426305.

It is not an unprimeable number, because it can be changed into a prime (1221426337) 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 3 ways as a sum of consecutive naturals, for example, 573456 + ... + 575581.

It is an arithmetic number, because the mean of its divisors is an integer number (305644108).

Almost surely, 2^1221426331 is an apocalyptic number.

1221426331 is a deficient number, since it is larger than the sum of its proper divisors (1150101).

1221426331 is a wasteful number, since it uses less digits than its factorization.

1221426331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1150100.

The product of its digits is 1728, while the sum is 25.

The square root of 1221426331 is about 34948.9102977475. The cubic root of 1221426331 is about 1068.9459824765.

Adding to 1221426331 its reverse (1336241221), we get a palindrome (2557667552).

The spelling of 1221426331 in words is "one billion, two hundred twenty-one million, four hundred twenty-six thousand, three hundred thirty-one".