76561229809 has 9 divisors (see below), whose sum is σ = 80808398073. Its totient is φ = 72526710852.

The previous prime is 76561229761. The next prime is 76561229827. The reversal of 76561229809 is 90892216567.

The square root of 76561229809 is 276697.

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

It is not a de Polignac number, because 76561229809 - 2¹³ = 76561221617 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 76561229809.

It is not an unprimeable number, because it can be changed into a prime (76561229309) 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, 5249962 + ... + 5264524.

It is an arithmetic number, because the mean of its divisors is an integer number (8978710897).

Almost surely, 2^76561229809 is an apocalyptic number.

76561229809 is the 276697-th square number.

76561229809 is the 138349-th centered octagonal number.

It is an amenable number.

76561229809 is a deficient number, since it is larger than the sum of its proper divisors (4247168264).

76561229809 is an frugal number, since it uses more digits than its factorization.

76561229809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29164 (or 14582 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 55.

The spelling of 76561229809 in words is "seventy-six billion, five hundred sixty-one million, two hundred twenty-nine thousand, eight hundred nine".