86666721 has 8 divisors (see below), whose sum is σ = 115624704. Its totient is φ = 57743280.

The previous prime is 86666719. The next prime is 86666729. The reversal of 86666721 is 12766668.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 86666721 - 2¹ = 86666719 is a prime.

It is a super-2 number, since 2×86666721² = 15022241057783682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (86666729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2065 + ... + 13326.

It is an arithmetic number, because the mean of its divisors is an integer number (14453088).

Almost surely, 2^86666721 is an apocalyptic number.

It is an amenable number.

86666721 is a deficient number, since it is larger than the sum of its proper divisors (28957983).

86666721 is a wasteful number, since it uses less digits than its factorization.

86666721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17271.

The product of its digits is 145152, while the sum is 42.

The square root of 86666721 is about 9309.4962806803. The cubic root of 86666721 is about 442.5382238997.

The spelling of 86666721 in words is "eighty-six million, six hundred sixty-six thousand, seven hundred twenty-one".