72720673 has 4 divisors (see below), whose sum is σ = 73184020. Its totient is φ = 72257328.

The previous prime is 72720667. The next prime is 72720689. The reversal of 72720673 is 37602727.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 29844369 + 42876304 = 5463^2 + 6548^2 .

It is a cyclic number.

It is not a de Polignac number, because 72720673 - 2⁹ = 72720161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72721673) 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, 231438 + ... + 231751.

It is an arithmetic number, because the mean of its divisors is an integer number (18296005).

Almost surely, 2^72720673 is an apocalyptic number.

It is an amenable number.

72720673 is a deficient number, since it is larger than the sum of its proper divisors (463347).

72720673 is a wasteful number, since it uses less digits than its factorization.

72720673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463346.

The product of its (nonzero) digits is 24696, while the sum is 34.

The square root of 72720673 is about 8527.6417021355. The cubic root of 72720673 is about 417.4001778871.

The spelling of 72720673 in words is "seventy-two million, seven hundred twenty thousand, six hundred seventy-three".