1291680720 has 240 divisors, whose sum is σ = 4885830144. Its totient is φ = 302976000.

The previous prime is 1291680701. The next prime is 1291680773. The reversal of 1291680720 is 270861921.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 242890 + ... + 248150.

Almost surely, 2^1291680720 is an apocalyptic number.

1291680720 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 1291680720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2442915072).

1291680720 is an abundant number, since it is smaller than the sum of its proper divisors (3594149424).

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

1291680720 is a wasteful number, since it uses less digits than its factorization.

1291680720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5322 (or 5313 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 1291680720 is about 35939.9599331997. The cubic root of 1291680720 is about 1089.0597958095.

It can be divided in two parts, 12916 and 80720, that added together give a square (93636 = 306²).

The spelling of 1291680720 in words is "one billion, two hundred ninety-one million, six hundred eighty thousand, seven hundred twenty".