82123841721 has 32 divisors (see below), whose sum is σ = 116760821760. Its totient is φ = 51197178816.

The previous prime is 82123841713. The next prime is 82123841729. The reversal of 82123841721 is 12714832128.

It is an interprime number because it is at equal distance from previous prime (82123841713) and next prime (82123841729).

It is not a de Polignac number, because 82123841721 - 2³ = 82123841713 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 82123841721.

It is not an unprimeable number, because it can be changed into a prime (82123841729) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1397290 + ... + 1454876.

It is an arithmetic number, because the mean of its divisors is an integer number (3648775680).

Almost surely, 2^82123841721 is an apocalyptic number.

It is an amenable number.

82123841721 is a deficient number, since it is larger than the sum of its proper divisors (34636980039).

82123841721 is a wasteful number, since it uses less digits than its factorization.

82123841721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57933.

The product of its digits is 43008, while the sum is 39.

The spelling of 82123841721 in words is "eighty-two billion, one hundred twenty-three million, eight hundred forty-one thousand, seven hundred twenty-one".