6720259991 has 8 divisors (see below), whose sum is σ = 7067664384. Its totient is φ = 6377457240.

The previous prime is 6720259963. The next prime is 6720259993. The reversal of 6720259991 is 1999520276.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6720259991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6720259993) 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, 1147415 + ... + 1153256.

It is an arithmetic number, because the mean of its divisors is an integer number (883458048).

Almost surely, 2^6720259991 is an apocalyptic number.

6720259991 is a deficient number, since it is larger than the sum of its proper divisors (347404393).

6720259991 is a wasteful number, since it uses less digits than its factorization.

6720259991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2300821.

The product of its (nonzero) digits is 612360, while the sum is 50.

The square root of 6720259991 is about 81977.1918950631. The cubic root of 6720259991 is about 1887.1019282805.

The spelling of 6720259991 in words is "six billion, seven hundred twenty million, two hundred fifty-nine thousand, nine hundred ninety-one".