6620440509 has 24 divisors (see below), whose sum is σ = 10176823800. Its totient is φ = 4132896768.

The previous prime is 6620440493. The next prime is 6620440513. The reversal of 6620440509 is 9050440266.

It can be written as a sum of positive squares in 4 ways, for example, as 5756256900 + 864183609 = 75870^2 + 29397^2 .

It is not a de Polignac number, because 6620440509 - 2⁴ = 6620440493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6620440709) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 79684 + ... + 139965.

It is an arithmetic number, because the mean of its divisors is an integer number (424034325).

Almost surely, 2^6620440509 is an apocalyptic number.

It is an amenable number.

6620440509 is a deficient number, since it is larger than the sum of its proper divisors (3556383291).

6620440509 is a wasteful number, since it uses less digits than its factorization.

6620440509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219869 (or 219866 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 6620440509 is about 81366.0894291965. The cubic root of 6620440509 is about 1877.7119165668.

The spelling of 6620440509 in words is "six billion, six hundred twenty million, four hundred forty thousand, five hundred nine".