721404041 has 4 divisors (see below), whose sum is σ = 735015492. Its totient is φ = 707792592.

The previous prime is 721403983. The next prime is 721404049. The reversal of 721404041 is 140404127.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 140404127 = 61 ⋅2301707.

It can be written as a sum of positive squares in 2 ways, for example, as 189640441 + 531763600 = 13771^2 + 23060^2 .

It is a cyclic number.

It is not a de Polignac number, because 721404041 - 2¹⁰ = 721403017 is a prime.

It is a super-2 number, since 2×721404041² = 1040847580742259362, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721403998 and 721404016.

It is not an unprimeable number, because it can be changed into a prime (721404049) 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, 6805646 + ... + 6805751.

It is an arithmetic number, because the mean of its divisors is an integer number (183753873).

Almost surely, 2^721404041 is an apocalyptic number.

It is an amenable number.

721404041 is a deficient number, since it is larger than the sum of its proper divisors (13611451).

721404041 is a wasteful number, since it uses less digits than its factorization.

721404041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13611450.

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 721404041 is about 26858.9657470276. The cubic root of 721404041 is about 896.8631706501.

Adding to 721404041 its reverse (140404127), we get a palindrome (861808168).

The spelling of 721404041 in words is "seven hundred twenty-one million, four hundred four thousand, forty-one".