723408821 has 16 divisors (see below), whose sum is σ = 748077120. Its totient is φ = 699262080.

The previous prime is 723408809. The next prime is 723408859. The reversal of 723408821 is 128804327.

It is a cyclic number.

It is not a de Polignac number, because 723408821 - 2¹⁴ = 723392437 is a prime.

It is a super-2 number, since 2×723408821² = 1046640644601220082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (723401821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1232090 + ... + 1232676.

It is an arithmetic number, because the mean of its divisors is an integer number (46754820).

Almost surely, 2^723408821 is an apocalyptic number.

It is an amenable number.

723408821 is a deficient number, since it is larger than the sum of its proper divisors (24668299).

723408821 is a wasteful number, since it uses less digits than its factorization.

723408821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 964.

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 723408821 is about 26896.2603534395. The cubic root of 723408821 is about 897.6931957372.

The spelling of 723408821 in words is "seven hundred twenty-three million, four hundred eight thousand, eight hundred twenty-one".