728320537 has 4 divisors (see below), whose sum is σ = 832366336. Its totient is φ = 624274740.

The previous prime is 728320517. The next prime is 728320573. The reversal of 728320537 is 735023827.

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: 735023827 = 14251 ⋅51577.

It is a cyclic number.

It is not a de Polignac number, because 728320537 - 2²⁷ = 594102809 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 728320496 and 728320505.

It is not an unprimeable number, because it can be changed into a prime (728320517) 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, 52022889 + ... + 52022902.

It is an arithmetic number, because the mean of its divisors is an integer number (208091584).

Almost surely, 2^728320537 is an apocalyptic number.

It is an amenable number.

728320537 is a deficient number, since it is larger than the sum of its proper divisors (104045799).

728320537 is a wasteful number, since it uses less digits than its factorization.

728320537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104045798.

The product of its (nonzero) digits is 70560, while the sum is 37.

The square root of 728320537 is about 26987.4144185767. The cubic root of 728320537 is about 899.7202986803.

The spelling of 728320537 in words is "seven hundred twenty-eight million, three hundred twenty thousand, five hundred thirty-seven".