82861821 has 24 divisors (see below), whose sum is σ = 137142720. Its totient is φ = 47226816.

The previous prime is 82861819. The next prime is 82861829. The reversal of 82861821 is 12816828.

It is not a de Polignac number, because 82861821 - 2¹ = 82861819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82861829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26425 + ... + 29393.

It is an arithmetic number, because the mean of its divisors is an integer number (5714280).

Almost surely, 2^82861821 is an apocalyptic number.

It is an amenable number.

82861821 is a deficient number, since it is larger than the sum of its proper divisors (54280899).

82861821 is a wasteful number, since it uses less digits than its factorization.

82861821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3425 (or 3422 counting only the distinct ones).

The product of its digits is 12288, while the sum is 36.

The square root of 82861821 is about 9102.8468623832. The cubic root of 82861821 is about 435.9648657966.

The spelling of 82861821 in words is "eighty-two million, eight hundred sixty-one thousand, eight hundred twenty-one".