6720725640 has 128 divisors (see below), whose sum is σ = 21053520000. Its totient is φ = 1714126848.

The previous prime is 6720725633. The next prime is 6720725647. The reversal of 6720725640 is 465270276.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (6720725633) and next prime (6720725647).

It is not an unprimeable number, because it can be changed into a prime (6720725647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 363336 + ... + 381384.

It is an arithmetic number, because the mean of its divisors is an integer number (164480625).

Almost surely, 2^6720725640 is an apocalyptic number.

6720725640 is a gapful number since it is divisible by the number (60) 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 6720725640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10526760000).

6720725640 is an abundant number, since it is smaller than the sum of its proper divisors (14332794360).

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

6720725640 is a wasteful number, since it uses less digits than its factorization.

6720725640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18199 (or 18195 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 39.

The square root of 6720725640 is about 81980.0319590082. The cubic root of 6720725640 is about 1887.1455132426.

The spelling of 6720725640 in words is "six billion, seven hundred twenty million, seven hundred twenty-five thousand, six hundred forty".