366865721 has 4 divisors (see below), whose sum is σ = 367216500. Its totient is φ = 366514944.

The previous prime is 366865711. The next prime is 366865757. The reversal of 366865721 is 127568663.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127568663 = 17 ⋅7504039.

It can be written as a sum of positive squares in 2 ways, for example, as 251539600 + 115326121 = 15860^2 + 10739^2 .

It is a cyclic number.

It is not a de Polignac number, because 366865721 - 2¹⁴ = 366849337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (366865711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 173816 + ... + 175913.

It is an arithmetic number, because the mean of its divisors is an integer number (91804125).

Almost surely, 2^366865721 is an apocalyptic number.

It is an amenable number.

366865721 is a deficient number, since it is larger than the sum of its proper divisors (350779).

366865721 is a wasteful number, since it uses less digits than its factorization.

366865721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350778.

The product of its digits is 362880, while the sum is 44.

The square root of 366865721 is about 19153.7390866640. The cubic root of 366865721 is about 715.8725526880.

The spelling of 366865721 in words is "three hundred sixty-six million, eight hundred sixty-five thousand, seven hundred twenty-one".