770721 has 20 divisors (see below), whose sum is σ = 1210032. Its totient is φ = 436296.

The previous prime is 770669. The next prime is 770741. The reversal of 770721 is 127077.

It is not a de Polignac number, because 770721 - 2⁶ = 770657 is a prime.

770721 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 770691 and 770700.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 770721.

It is not an unprimeable number, because it can be changed into a prime (770741) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7150 + ... + 7256.

2⁷⁷⁰⁷²¹ is an apocalyptic number.

It is an amenable number.

770721 is a deficient number, since it is larger than the sum of its proper divisors (439311).

770721 is an equidigital number, since it uses as much as digits as its factorization.

770721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 686, while the sum is 24.

The square root of 770721 is about 877.9071704913. The cubic root of 770721 is about 91.6851635768.

Adding to 770721 its reverse (127077), we get a palindrome (897798).

The spelling of 770721 in words is "seven hundred seventy thousand, seven hundred twenty-one", and thus it is an iban number.