72971785 has 4 divisors (see below), whose sum is σ = 87566148. Its totient is φ = 58377424.

The previous prime is 72971771. The next prime is 72971791. The reversal of 72971785 is 58717927.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58717927 = 37 ⋅1586971.

It can be written as a sum of positive squares in 2 ways, for example, as 25030009 + 47941776 = 5003^2 + 6924^2 .

It is a cyclic number.

It is not a de Polignac number, because 72971785 - 2¹¹ = 72969737 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7297174 + ... + 7297183.

It is an arithmetic number, because the mean of its divisors is an integer number (21891537).

Almost surely, 2^72971785 is an apocalyptic number.

It is an amenable number.

72971785 is a deficient number, since it is larger than the sum of its proper divisors (14594363).

72971785 is a wasteful number, since it uses less digits than its factorization.

72971785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14594362.

The product of its digits is 246960, while the sum is 46.

The square root of 72971785 is about 8542.3524277567. The cubic root of 72971785 is about 417.8800679253.

It can be divided in two parts, 7 and 2971785, that added together give a palindrome (2971792).

The spelling of 72971785 in words is "seventy-two million, nine hundred seventy-one thousand, seven hundred eighty-five".