82507821 has 16 divisors (see below), whose sum is σ = 120184128. Its totient is φ = 49932800.

The previous prime is 82507811. The next prime is 82507849. The reversal of 82507821 is 12870528.

It is a cyclic number.

It is not a de Polignac number, because 82507821 - 2⁶ = 82507757 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82507811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29725 + ... + 32381.

It is an arithmetic number, because the mean of its divisors is an integer number (7511508).

Almost surely, 2^82507821 is an apocalyptic number.

It is an amenable number.

82507821 is a deficient number, since it is larger than the sum of its proper divisors (37676307).

82507821 is a wasteful number, since it uses less digits than its factorization.

82507821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3612.

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 82507821 is about 9083.3815839697. The cubic root of 82507821 is about 435.3431405326.

The spelling of 82507821 in words is "eighty-two million, five hundred seven thousand, eight hundred twenty-one".