1321506531 has 6 divisors (see below), whose sum is σ = 1908842780. Its totient is φ = 881004348.

The previous prime is 1321506503. The next prime is 1321506569. The reversal of 1321506531 is 1356051231.

1321506531 is a `hidden beast` number, since 1 + 3 + 2 + 1 + 5 + 0 + 653 + 1 = 666.

1321506531 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1321506531 - 2¹⁸ = 1321244387 is a prime.

It is a super-2 number, since 2×1321506531² = 3492759022951307922, 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 = 1321506495 and 1321506504.

It is not an unprimeable number, because it can be changed into a prime (1321506581) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73417021 + ... + 73417038.

Almost surely, 2^1321506531 is an apocalyptic number.

1321506531 is a deficient number, since it is larger than the sum of its proper divisors (587336249).

1321506531 is a wasteful number, since it uses less digits than its factorization.

1321506531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146834065 (or 146834062 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 1321506531 is about 36352.5312873808. The cubic root of 1321506531 is about 1097.3784766243.

Adding to 1321506531 its reverse (1356051231), we get a palindrome (2677557762).

The spelling of 1321506531 in words is "one billion, three hundred twenty-one million, five hundred six thousand, five hundred thirty-one".