82785021 has 16 divisors (see below), whose sum is σ = 123670848. Its totient is φ = 48816000.

The previous prime is 82785013. The next prime is 82785023. The reversal of 82785021 is 12058728.

It is not a de Polignac number, because 82785021 - 2³ = 82785013 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 (82785023) 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, 32680 + ... + 35121.

It is an arithmetic number, because the mean of its divisors is an integer number (7729428).

Almost surely, 2^82785021 is an apocalyptic number.

It is an amenable number.

82785021 is a deficient number, since it is larger than the sum of its proper divisors (40885827).

82785021 is a wasteful number, since it uses less digits than its factorization.

82785021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67852.

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

The square root of 82785021 is about 9098.6274239580. The cubic root of 82785021 is about 435.8301336572.

The spelling of 82785021 in words is "eighty-two million, seven hundred eighty-five thousand, twenty-one".