82670721 has 16 divisors (see below), whose sum is σ = 126640128. Its totient is φ = 46990800.

The previous prime is 82670699. The next prime is 82670737. The reversal of 82670721 is 12707628.

It is not a de Polignac number, because 82670721 - 2⁶ = 82670657 is a prime.

It is a super-2 number, since 2×82670721² = 13668896221319682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (82670221) 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 in 15 ways as a sum of consecutive naturals, for example, 6295 + ... + 14316.

It is an arithmetic number, because the mean of its divisors is an integer number (7915008).

Almost surely, 2^82670721 is an apocalyptic number.

It is an amenable number.

82670721 is a deficient number, since it is larger than the sum of its proper divisors (43969407).

82670721 is a wasteful number, since it uses less digits than its factorization.

82670721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20812.

The product of its (nonzero) digits is 9408, while the sum is 33.

The square root of 82670721 is about 9092.3440871978. The cubic root of 82670721 is about 435.6294599616.

The spelling of 82670721 in words is "eighty-two million, six hundred seventy thousand, seven hundred twenty-one".