1320640660 has 48 divisors (see below), whose sum is σ = 2828750400. Its totient is φ = 517757184.

The previous prime is 1320640637. The next prime is 1320640661. The reversal of 1320640660 is 660460231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1320640661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 445744 + ... + 448696.

It is an arithmetic number, because the mean of its divisors is an integer number (58932300).

Almost surely, 2^1320640660 is an apocalyptic number.

1320640660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1320640660 is an abundant number, since it is smaller than the sum of its proper divisors (1508109740).

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

1320640660 is a wasteful number, since it uses less digits than its factorization.

1320640660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3400 (or 3398 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 1320640660 is about 36340.6199726972. The cubic root of 1320640660 is about 1097.1387512861.

The spelling of 1320640660 in words is "one billion, three hundred twenty million, six hundred forty thousand, six hundred sixty".