1321540660 has 24 divisors (see below), whose sum is σ = 3027530016. Its totient is φ = 480560160.

The previous prime is 1321540657. The next prime is 1321540667. The reversal of 1321540660 is 660451231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321540667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3003282 + ... + 3003721.

It is an arithmetic number, because the mean of its divisors is an integer number (126147084).

Almost surely, 2^1321540660 is an apocalyptic number.

1321540660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321540660 is an abundant number, since it is smaller than the sum of its proper divisors (1705989356).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1321540660 is a wasteful number, since it uses less digits than its factorization.

1321540660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6007023 (or 6007021 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 1321540660 is about 36353.0007014552. Note that the first 3 decimals coincide. The cubic root of 1321540660 is about 1097.3879234455.

Adding to 1321540660 its reverse (660451231), we get a palindrome (1981991891).

The spelling of 1321540660 in words is "one billion, three hundred twenty-one million, five hundred forty thousand, six hundred sixty".