769723720921 has 9 divisors (see below), whose sum is σ = 772466344479. Its totient is φ = 766990809936.

The previous prime is 769723720889. The next prime is 769723720943. The reversal of 769723720921 is 129027327967.

It is a happy number.

The square root of 769723720921 is 877339.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4910505625 + 764813215296 = 70075^2 + 874536^2 .

It is not a de Polignac number, because 769723720921 - 2⁵ = 769723720889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (769723720121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 274605706 + ... + 274608508.

It is an arithmetic number, because the mean of its divisors is an integer number (85829593831).

Almost surely, 2^769723720921 is an apocalyptic number.

769723720921 is the 877339-th square number.

769723720921 is the 438670-th centered octagonal number.

It is an amenable number.

769723720921 is a deficient number, since it is larger than the sum of its proper divisors (2742623558).

769723720921 is an frugal number, since it uses more digits than its factorization.

769723720921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6232 (or 3116 counting only the distinct ones).

The product of its (nonzero) digits is 4000752, while the sum is 55.

The spelling of 769723720921 in words is "seven hundred sixty-nine billion, seven hundred twenty-three million, seven hundred twenty thousand, nine hundred twenty-one".