864721441 has 4 divisors (see below), whose sum is σ = 864982084. Its totient is φ = 864460800.

The previous prime is 864721433. The next prime is 864721477. The reversal of 864721441 is 144127468.

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 338707216 + 526014225 = 18404^2 + 22935^2 .

It is a cyclic number.

It is not a de Polignac number, because 864721441 - 2³ = 864721433 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 864721441.

It is not an unprimeable number, because it can be changed into a prime (864721411) 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 3 ways as a sum of consecutive naturals, for example, 125280 + ... + 132001.

It is an arithmetic number, because the mean of its divisors is an integer number (216245521).

Almost surely, 2^864721441 is an apocalyptic number.

It is an amenable number.

864721441 is a deficient number, since it is larger than the sum of its proper divisors (260643).

864721441 is a wasteful number, since it uses less digits than its factorization.

864721441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260642.

The product of its digits is 43008, while the sum is 37.

The square root of 864721441 is about 29406.1463133135. The cubic root of 864721441 is about 952.7056537730.

The spelling of 864721441 in words is "eight hundred sixty-four million, seven hundred twenty-one thousand, four hundred forty-one".