72705439 has 4 divisors (see below), whose sum is σ = 73023160. Its totient is φ = 72387720.

The previous prime is 72705403. The next prime is 72705449. The reversal of 72705439 is 93450727.

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

It is a cyclic number.

It is not a de Polignac number, because 72705439 - 2⁹ = 72704927 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72705398 and 72705407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72705449) 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, 158517 + ... + 158974.

It is an arithmetic number, because the mean of its divisors is an integer number (18255790).

Almost surely, 2^72705439 is an apocalyptic number.

72705439 is a deficient number, since it is larger than the sum of its proper divisors (317721).

72705439 is a wasteful number, since it uses less digits than its factorization.

72705439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317720.

The product of its (nonzero) digits is 52920, while the sum is 37.

The square root of 72705439 is about 8526.7484424017. The cubic root of 72705439 is about 417.3710292828.

The spelling of 72705439 in words is "seventy-two million, seven hundred five thousand, four hundred thirty-nine".