80670721 has 4 divisors (see below), whose sum is σ = 83452500. Its totient is φ = 77888944.

The previous prime is 80670691. The next prime is 80670749. The reversal of 80670721 is 12707608.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62489025 + 18181696 = 7905^2 + 4264^2 .

It is a cyclic number.

It is not a de Polignac number, because 80670721 - 2⁹ = 80670209 is a prime.

It is a super-3 number, since 3×80670721³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80670761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1390846 + ... + 1390903.

It is an arithmetic number, because the mean of its divisors is an integer number (20863125).

Almost surely, 2^80670721 is an apocalyptic number.

It is an amenable number.

80670721 is a deficient number, since it is larger than the sum of its proper divisors (2781779).

80670721 is a wasteful number, since it uses less digits than its factorization.

80670721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2781778.

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 80670721 is about 8981.6880930035. The cubic root of 80670721 is about 432.0877754456.

The spelling of 80670721 in words is "eighty million, six hundred seventy thousand, seven hundred twenty-one".