82125621 has 6 divisors (see below), whose sum is σ = 118625910. Its totient is φ = 54750408.

The previous prime is 82125613. The next prime is 82125647. The reversal of 82125621 is 12652128.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 45037521 + 37088100 = 6711^2 + 6090^2 .

It is not a de Polignac number, because 82125621 - 2³ = 82125613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82125611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4562526 + ... + 4562543.

It is an arithmetic number, because the mean of its divisors is an integer number (19770985).

Almost surely, 2^82125621 is an apocalyptic number.

It is an amenable number.

82125621 is a deficient number, since it is larger than the sum of its proper divisors (36500289).

82125621 is a wasteful number, since it uses less digits than its factorization.

82125621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9125075 (or 9125072 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 82125621 is about 9062.3187430149. The cubic root of 82125621 is about 434.6698882727.

Adding to 82125621 its reverse (12652128), we get a palindrome (94777749).

The spelling of 82125621 in words is "eighty-two million, one hundred twenty-five thousand, six hundred twenty-one".