82154521 has 2 divisors, whose sum is σ = 82154522. Its totient is φ = 82154520.

The previous prime is 82154519. The next prime is 82154539. The reversal of 82154521 is 12545128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66194496 + 15960025 = 8136^2 + 3995^2 .

It is a cyclic number.

It is not a de Polignac number, because 82154521 - 2¹ = 82154519 is a prime.

Together with 82154519, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 82154521.

It is not a weakly prime, because it can be changed into another prime (82154561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41077260 + 41077261.

It is an arithmetic number, because the mean of its divisors is an integer number (41077261).

Almost surely, 2^82154521 is an apocalyptic number.

It is an amenable number.

82154521 is a deficient number, since it is larger than the sum of its proper divisors (1).

82154521 is an equidigital number, since it uses as much as digits as its factorization.

82154521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3200, while the sum is 28.

The square root of 82154521 is about 9063.9131174124. The cubic root of 82154521 is about 434.7208690604.

Adding to 82154521 its reverse (12545128), we get a palindrome (94699649).

The spelling of 82154521 in words is "eighty-two million, one hundred fifty-four thousand, five hundred twenty-one".