7729750561 has 9 divisors (see below), whose sum is σ = 8371322739. Its totient is φ = 7134099336.

The previous prime is 7729750559. The next prime is 7729750571. The reversal of 7729750561 is 1650579277.

It is a happy number.

The square root of 7729750561 is 87919.

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., 1143454225 + 6586296336 = 33815^2 + 81156^2 .

It is not a de Polignac number, because 7729750561 - 2¹ = 7729750559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7729750531) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1139566 + ... + 1146328.

It is an arithmetic number, because the mean of its divisors is an integer number (930146971).

Almost surely, 2^7729750561 is an apocalyptic number.

7729750561 is the 87919-th square number.

7729750561 is the 43960-th centered octagonal number.

It is an amenable number.

7729750561 is a deficient number, since it is larger than the sum of its proper divisors (641572178).

7729750561 is an frugal number, since it uses more digits than its factorization.

7729750561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13552 (or 6776 counting only the distinct ones).

The product of its (nonzero) digits is 926100, while the sum is 49.

The cubic root of 7729750561 is about 1977.2207513334.

Multiplying 7729750561 by its sum of digits (49), we get a square (378757777489 = 615433²).

The spelling of 7729750561 in words is "seven billion, seven hundred twenty-nine million, seven hundred fifty thousand, five hundred sixty-one".