1213021331 has 4 divisors (see below), whose sum is σ = 1213968072. Its totient is φ = 1212074592.

The previous prime is 1213021321. The next prime is 1213021339. The reversal of 1213021331 is 1331203121.

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 1213021331 - 2⁶ = 1213021267 is a prime.

It is a super-2 number, since 2×1213021331² = 2942841498922023122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213021339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 471446 + ... + 474011.

It is an arithmetic number, because the mean of its divisors is an integer number (303492018).

Almost surely, 2^1213021331 is an apocalyptic number.

1213021331 is a deficient number, since it is larger than the sum of its proper divisors (946741).

1213021331 is an equidigital number, since it uses as much as digits as its factorization.

1213021331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 946740.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1213021331 is about 34828.4557653652. The cubic root of 1213021331 is about 1066.4884243945.

Adding to 1213021331 its reverse (1331203121), we get a palindrome (2544224452).

The spelling of 1213021331 in words is "one billion, two hundred thirteen million, twenty-one thousand, three hundred thirty-one".