1308992640 has 128 divisors (see below), whose sum is σ = 4184611200. Its totient is φ = 348045312.

The previous prime is 1308992617. The next prime is 1308992647. The reversal of 1308992640 is 462998031.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 1308992592 and 1308992601.

It is not an unprimeable number, because it can be changed into a prime (1308992647) 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, 842104 + ... + 843656.

It is an arithmetic number, because the mean of its divisors is an integer number (32692275).

Almost surely, 2^1308992640 is an apocalyptic number.

1308992640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1308992640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2092305600).

1308992640 is an abundant number, since it is smaller than the sum of its proper divisors (2875618560).

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

1308992640 is a wasteful number, since it uses less digits than its factorization.

1308992640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2014 (or 2002 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 42.

The square root of 1308992640 is about 36180.0033167494. The cubic root of 1308992640 is about 1093.9036419158.

The spelling of 1308992640 in words is "one billion, three hundred eight million, nine hundred ninety-two thousand, six hundred forty".