82420259821 has 4 divisors (see below), whose sum is σ = 82465772544. Its totient is φ = 82374747100.

The previous prime is 82420259743. The next prime is 82420259827. The reversal of 82420259821 is 12895202428.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 82420259821 - 2¹³ = 82420251629 is a prime.

It is a super-2 number, since 2×82420259821² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82420259827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22753645 + ... + 22757266.

It is an arithmetic number, because the mean of its divisors is an integer number (20616443136).

Almost surely, 2^82420259821 is an apocalyptic number.

It is an amenable number.

82420259821 is a deficient number, since it is larger than the sum of its proper divisors (45512723).

82420259821 is a wasteful number, since it uses less digits than its factorization.

82420259821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45512722.

The product of its (nonzero) digits is 184320, while the sum is 43.

The spelling of 82420259821 in words is "eighty-two billion, four hundred twenty million, two hundred fifty-nine thousand, eight hundred twenty-one".