6720351621 has 16 divisors (see below), whose sum is σ = 9173043264. Its totient is φ = 4374042624.

The previous prime is 6720351607. The next prime is 6720351643. The reversal of 6720351621 is 1261530276.

It is not a de Polignac number, because 6720351621 - 2¹³ = 6720343429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6720351601) 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 15 ways as a sum of consecutive naturals, for example, 303685 + ... + 325061.

It is an arithmetic number, because the mean of its divisors is an integer number (573315204).

Almost surely, 2^6720351621 is an apocalyptic number.

It is an amenable number.

6720351621 is a deficient number, since it is larger than the sum of its proper divisors (2452691643).

6720351621 is a wasteful number, since it uses less digits than its factorization.

6720351621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23860.

The product of its (nonzero) digits is 15120, while the sum is 33.

The square root of 6720351621 is about 81977.7507681200. The cubic root of 6720351621 is about 1887.1105050501.

Adding to 6720351621 its reverse (1261530276), we get a palindrome (7981881897).

The spelling of 6720351621 in words is "six billion, seven hundred twenty million, three hundred fifty-one thousand, six hundred twenty-one".