721135441 has 4 divisors (see below), whose sum is σ = 776607412. Its totient is φ = 665663472.

The previous prime is 721135403. The next prime is 721135451. The reversal of 721135441 is 144531127.

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 60902416 + 660233025 = 7804^2 + 25695^2 .

It is a cyclic number.

It is not a de Polignac number, because 721135441 - 2¹⁵ = 721102673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721135451) 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, 27735966 + ... + 27735991.

It is an arithmetic number, because the mean of its divisors is an integer number (194151853).

Almost surely, 2^721135441 is an apocalyptic number.

It is an amenable number.

721135441 is a deficient number, since it is larger than the sum of its proper divisors (55471971).

721135441 is a wasteful number, since it uses less digits than its factorization.

721135441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55471970.

The product of its digits is 3360, while the sum is 28.

The square root of 721135441 is about 26853.9650889771. The cubic root of 721135441 is about 896.7518472965.

Adding to 721135441 its reverse (144531127), we get a palindrome (865666568).

The spelling of 721135441 in words is "seven hundred twenty-one million, one hundred thirty-five thousand, four hundred forty-one".