1321501531 has 12 divisors (see below), whose sum is σ = 1537982208. Its totient is φ = 1132181232.

The previous prime is 1321501513. The next prime is 1321501537. The reversal of 1321501531 is 1351051231.

It is not a de Polignac number, because 1321501531 - 2²⁷ = 1187283803 is a prime.

It is a super-2 number, since 2×1321501531² = 3492732592870687922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1321501537) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 126645 + ... + 136681.

It is an arithmetic number, because the mean of its divisors is an integer number (128165184).

Almost surely, 2^1321501531 is an apocalyptic number.

1321501531 is a deficient number, since it is larger than the sum of its proper divisors (216480677).

1321501531 is a wasteful number, since it uses less digits than its factorization.

1321501531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12738 (or 12731 counting only the distinct ones).

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 1321501531 is about 36352.4625163138. The cubic root of 1321501531 is about 1097.3770926233.

Adding to 1321501531 its reverse (1351051231), we get a palindrome (2672552762).

The spelling of 1321501531 in words is "one billion, three hundred twenty-one million, five hundred one thousand, five hundred thirty-one".