82987921 has 2 divisors, whose sum is σ = 82987922. Its totient is φ = 82987920.

The previous prime is 82987909. The next prime is 82987951. The reversal of 82987921 is 12978928.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65044225 + 17943696 = 8065^2 + 4236^2 .

It is a cyclic number.

It is not a de Polignac number, because 82987921 - 2¹⁵ = 82955153 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (82987951) 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 as a sum of consecutive naturals, namely, 41493960 + 41493961.

It is an arithmetic number, because the mean of its divisors is an integer number (41493961).

Almost surely, 2^82987921 is an apocalyptic number.

It is an amenable number.

82987921 is a deficient number, since it is larger than the sum of its proper divisors (1).

82987921 is an equidigital number, since it uses as much as digits as its factorization.

82987921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 46.

The square root of 82987921 is about 9109.7706337756. The cubic root of 82987921 is about 436.1859056966.

The spelling of 82987921 in words is "eighty-two million, nine hundred eighty-seven thousand, nine hundred twenty-one".