1331220511 has 4 divisors (see below), whose sum is σ = 1339387672. Its totient is φ = 1323053352.

The previous prime is 1331220509. The next prime is 1331220533. The reversal of 1331220511 is 1150221331.

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 1331220511 - 2¹ = 1331220509 is a prime.

It is a super-2 number, since 2×1331220511² = 3544296097814202242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331220811) 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, 4083336 + ... + 4083661.

It is an arithmetic number, because the mean of its divisors is an integer number (334846918).

Almost surely, 2^1331220511 is an apocalyptic number.

1331220511 is a deficient number, since it is larger than the sum of its proper divisors (8167161).

1331220511 is an equidigital number, since it uses as much as digits as its factorization.

1331220511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8167160.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 1331220511 is about 36485.8946854809. The cubic root of 1331220511 is about 1100.0607434776.

Adding to 1331220511 its reverse (1150221331), we get a palindrome (2481441842).

The spelling of 1331220511 in words is "one billion, three hundred thirty-one million, two hundred twenty thousand, five hundred eleven".