1331431521 has 16 divisors (see below), whose sum is σ = 2117059584. Its totient is φ = 727738704.

The previous prime is 1331431501. The next prime is 1331431523. The reversal of 1331431521 is 1251341331.

It is not a de Polignac number, because 1331431521 - 2⁷ = 1331431393 is a prime.

It is a super-2 number, since 2×1331431521² = 3545419790224746882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1331431491 and 1331431500.

It is not an unprimeable number, because it can be changed into a prime (1331431523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1377811 + ... + 1378776.

It is an arithmetic number, because the mean of its divisors is an integer number (132316224).

Almost surely, 2^1331431521 is an apocalyptic number.

It is an amenable number.

1331431521 is a deficient number, since it is larger than the sum of its proper divisors (785628063).

1331431521 is a wasteful number, since it uses less digits than its factorization.

1331431521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2756620.

The product of its digits is 1080, while the sum is 24.

The square root of 1331431521 is about 36488.7862363220. The cubic root of 1331431521 is about 1100.1188634640.

Adding to 1331431521 its reverse (1251341331), we get a palindrome (2582772852).

The spelling of 1331431521 in words is "one billion, three hundred thirty-one million, four hundred thirty-one thousand, five hundred twenty-one".