7720644 has 24 divisors (see below), whose sum is σ = 18123840. Its totient is φ = 2557984.

The previous prime is 7720639. The next prime is 7720649. The reversal of 7720644 is 4460277.

It is an interprime number because it is at equal distance from previous prime (7720639) and next prime (7720649).

It is not an unprimeable number, because it can be changed into a prime (7720649) 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, 217 + ... + 3935.

It is an arithmetic number, because the mean of its divisors is an integer number (755160).

Almost surely, 2^7720644 is an apocalyptic number.

It is an amenable number.

7720644 is an abundant number, since it is smaller than the sum of its proper divisors (10403196).

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

7720644 is a wasteful number, since it uses less digits than its factorization.

7720644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3899 (or 3897 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 30.

The square root of 7720644 is about 2778.6046858090. The cubic root of 7720644 is about 197.6443979525.

The spelling of 7720644 in words is "seven million, seven hundred twenty thousand, six hundred forty-four".