82122721 has 8 divisors (see below), whose sum is σ = 84991104. Its totient is φ = 79288560.

The previous prime is 82122697. The next prime is 82122727. The reversal of 82122721 is 12722128.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 82122721 - 2¹⁷ = 81991649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82122727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3625 + ... + 13318.

It is an arithmetic number, because the mean of its divisors is an integer number (10623888).

Almost surely, 2^82122721 is an apocalyptic number.

It is an amenable number.

82122721 is a deficient number, since it is larger than the sum of its proper divisors (2868383).

82122721 is a wasteful number, since it uses less digits than its factorization.

82122721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17111.

The product of its digits is 896, while the sum is 25.

The square root of 82122721 is about 9062.1587384022. The cubic root of 82122721 is about 434.6647718933.

Adding to 82122721 its reverse (12722128), we get a palindrome (94844849).

The spelling of 82122721 in words is "eighty-two million, one hundred twenty-two thousand, seven hundred twenty-one".