7728139331 has 8 divisors (see below), whose sum is σ = 8514170928. Its totient is φ = 6956020000.

The previous prime is 7728139303. The next prime is 7728139339. The reversal of 7728139331 is 1339318277.

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-7728139331 is a prime.

It is a super-2 number, since 2×7728139331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7728139339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3476900 + ... + 3479121.

It is an arithmetic number, because the mean of its divisors is an integer number (1064271366).

Almost surely, 2^7728139331 is an apocalyptic number.

7728139331 is a deficient number, since it is larger than the sum of its proper divisors (786031597).

7728139331 is a wasteful number, since it uses less digits than its factorization.

7728139331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6956133.

The product of its digits is 190512, while the sum is 44.

The square root of 7728139331 is about 87909.8363722741. The cubic root of 7728139331 is about 1977.0833610108.

The spelling of 7728139331 in words is "seven billion, seven hundred twenty-eight million, one hundred thirty-nine thousand, three hundred thirty-one".