1321081521 has 16 divisors (see below), whose sum is σ = 1841909760. Its totient is φ = 840649040.

The previous prime is 1321081513. The next prime is 1321081549. The reversal of 1321081521 is 1251801231.

It is a cyclic number.

It is not a de Polignac number, because 1321081521 - 2³ = 1321081513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1321081491 and 1321081500.

It is not an unprimeable number, because it can be changed into a prime (1321081621) 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 15 ways as a sum of consecutive naturals, for example, 13066 + ... + 53036.

It is an arithmetic number, because the mean of its divisors is an integer number (115119360).

Almost surely, 2^1321081521 is an apocalyptic number.

It is an amenable number.

1321081521 is a deficient number, since it is larger than the sum of its proper divisors (520828239).

1321081521 is a wasteful number, since it uses less digits than its factorization.

1321081521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40476.

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 1321081521 is about 36346.6851445906. The cubic root of 1321081521 is about 1097.2608213010.

Adding to 1321081521 its reverse (1251801231), we get a palindrome (2572882752).

The spelling of 1321081521 in words is "one billion, three hundred twenty-one million, eighty-one thousand, five hundred twenty-one".