79781956849 has 9 divisors (see below), whose sum is σ = 92809882521. Its totient is φ = 68382839700.

The previous prime is 79781956823. The next prime is 79781956853. The reversal of 79781956849 is 94865918797.

The square root of 79781956849 is 282457.

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

It is not a de Polignac number, because 79781956849 - 2¹⁹ = 79781432561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79781956249) 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, 1957024 + ... + 1997374.

It is an arithmetic number, because the mean of its divisors is an integer number (10312209169).

Almost surely, 2^79781956849 is an apocalyptic number.

79781956849 is the 282457-th square number.

79781956849 is the 141229-th centered octagonal number.

It is an amenable number.

79781956849 is a deficient number, since it is larger than the sum of its proper divisors (13027925672).

79781956849 is an frugal number, since it uses more digits than its factorization.

79781956849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80716 (or 40358 counting only the distinct ones).

The product of its digits is 274337280, while the sum is 73.

The spelling of 79781956849 in words is "seventy-nine billion, seven hundred eighty-one million, nine hundred fifty-six thousand, eight hundred forty-nine".