61765669729 has 9 divisors (see below), whose sum is σ = 63830344851. Its totient is φ = 59765772960.

The previous prime is 61765669717. The next prime is 61765669739. The reversal of 61765669729 is 92796656716.

The square root of 61765669729 is 248527.

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., 35700213025 + 26065456704 = 188945^2 + 161448^2 .

It is not a de Polignac number, because 61765669729 - 2¹⁷ = 61765538657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61765669739) 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, 7700329 + ... + 7708345.

It is an arithmetic number, because the mean of its divisors is an integer number (7092260539).

Almost surely, 2^61765669729 is an apocalyptic number.

61765669729 is the 248527-th square number.

61765669729 is the 124264-th centered octagonal number.

It is an amenable number.

61765669729 is a deficient number, since it is larger than the sum of its proper divisors (2064675122).

61765669729 is an frugal number, since it uses more digits than its factorization.

61765669729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16096 (or 8048 counting only the distinct ones).

The product of its digits is 51438240, while the sum is 64.

Multiplying 61765669729 by its sum of digits (64), we get a square (3953002862656 = 1988216²).

The spelling of 61765669729 in words is "sixty-one billion, seven hundred sixty-five million, six hundred sixty-nine thousand, seven hundred twenty-nine".