82908867721 has 3 divisors (see below), whose sum is σ = 82909155661. Its totient is φ = 82908579782.

The previous prime is 82908867719. The next prime is 82908867749. The reversal of 82908867721 is 12776880928.

The square root of 82908867721 is 287939.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 82908867721 - 2¹ = 82908867719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82908067721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 143970 + ... + 431908.

Almost surely, 2^82908867721 is an apocalyptic number.

82908867721 is the 287939-th square number.

82908867721 is the 143970-th centered octagonal number.

It is an amenable number.

82908867721 is a deficient number, since it is larger than the sum of its proper divisors (287940).

82908867721 is an frugal number, since it uses more digits than its factorization.

82908867721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575878 (or 287939 counting only the distinct ones).

The product of its (nonzero) digits is 5419008, while the sum is 58.

It can be divided in two parts, 829088 and 67721, that added together give a square (896809 = 947²).

The spelling of 82908867721 in words is "eighty-two billion, nine hundred eight million, eight hundred sixty-seven thousand, seven hundred twenty-one".