86704721 has 4 divisors (see below), whose sum is σ = 86776500. Its totient is φ = 86632944.

The previous prime is 86704699. The next prime is 86704741. The reversal of 86704721 is 12740768.

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 85359121 + 1345600 = 9239^2 + 1160^2 .

It is a cyclic number.

It is not a de Polignac number, because 86704721 - 2²⁶ = 19595857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (86704741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34046 + ... + 36503.

It is an arithmetic number, because the mean of its divisors is an integer number (21694125).

Almost surely, 2^86704721 is an apocalyptic number.

It is an amenable number.

86704721 is a deficient number, since it is larger than the sum of its proper divisors (71779).

86704721 is a wasteful number, since it uses less digits than its factorization.

86704721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71778.

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 86704721 is about 9311.5369837637. The cubic root of 86704721 is about 442.6028930719.

The spelling of 86704721 in words is "eighty-six million, seven hundred four thousand, seven hundred twenty-one".