7720681 has 4 divisors (see below), whose sum is σ = 7851600. Its totient is φ = 7589764.

The previous prime is 7720673. The next prime is 7720697. The reversal of 7720681 is 1860277.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 7720681 - 2³ = 7720673 is a prime.

It is a super-2 number, since 2×7720681² = 119217830207522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7720621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65371 + ... + 65488.

It is an arithmetic number, because the mean of its divisors is an integer number (1962900).

Almost surely, 2^7720681 is an apocalyptic number.

It is an amenable number.

7720681 is a deficient number, since it is larger than the sum of its proper divisors (130919).

7720681 is a wasteful number, since it uses less digits than its factorization.

7720681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130918.

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 7720681 is about 2778.6113438191. The cubic root of 7720681 is about 197.6447136788.

The spelling of 7720681 in words is "seven million, seven hundred twenty thousand, six hundred eighty-one".