724843021 has 4 divisors (see below), whose sum is σ = 828392032. Its totient is φ = 621294012.

The previous prime is 724843003. The next prime is 724843037. The reversal of 724843021 is 120348427.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120348427 = 4049 ⋅29723.

It is a cyclic number.

It is not a de Polignac number, because 724843021 - 2¹³ = 724834829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (724843001) 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, 51774495 + ... + 51774508.

It is an arithmetic number, because the mean of its divisors is an integer number (207098008).

Almost surely, 2^724843021 is an apocalyptic number.

It is an amenable number.

724843021 is a deficient number, since it is larger than the sum of its proper divisors (103549011).

724843021 is a wasteful number, since it uses less digits than its factorization.

724843021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103549010.

The product of its (nonzero) digits is 10752, while the sum is 31.

The square root of 724843021 is about 26922.9088510139. The cubic root of 724843021 is about 898.2860470871.

The spelling of 724843021 in words is "seven hundred twenty-four million, eight hundred forty-three thousand, twenty-one".