6720409128 has 32 divisors (see below), whose sum is σ = 17789319360. Its totient is φ = 2108363520.

The previous prime is 6720409109. The next prime is 6720409147. The reversal of 6720409128 is 8219040276.

It is an interprime number because it is at equal distance from previous prime (6720409109) and next prime (6720409147).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8235388 + ... + 8236203.

It is an arithmetic number, because the mean of its divisors is an integer number (555916230).

Almost surely, 2^6720409128 is an apocalyptic number.

6720409128 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

6720409128 is an abundant number, since it is smaller than the sum of its proper divisors (11068910232).

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

6720409128 is a wasteful number, since it uses less digits than its factorization.

6720409128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16471617 (or 16471613 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 6720409128 is about 81978.1015149778. The cubic root of 6720409128 is about 1887.1158877920.

The spelling of 6720409128 in words is "six billion, seven hundred twenty million, four hundred nine thousand, one hundred twenty-eight".