723223021 has 4 divisors (see below), whose sum is σ = 723278844. Its totient is φ = 723167200.

The previous prime is 723223019. The next prime is 723223031. The reversal of 723223021 is 120322327.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 620707396 + 102515625 = 24914^2 + 10125^2 .

It is a cyclic number.

It is not a de Polignac number, because 723223021 - 2¹ = 723223019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 723222983 and 723223001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (723223031) 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, 2751 + ... + 38131.

It is an arithmetic number, because the mean of its divisors is an integer number (180819711).

Almost surely, 2^723223021 is an apocalyptic number.

It is an amenable number.

723223021 is a deficient number, since it is larger than the sum of its proper divisors (55823).

723223021 is a wasteful number, since it uses less digits than its factorization.

723223021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55822.

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 723223021 is about 26892.8061198529. The cubic root of 723223021 is about 897.6163347827.

Adding to 723223021 its reverse (120322327), we get a palindrome (843545348).

The spelling of 723223021 in words is "seven hundred twenty-three million, two hundred twenty-three thousand, twenty-one".