72972709 has 2 divisors, whose sum is σ = 72972710. Its totient is φ = 72972708.

The previous prime is 72972707. The next prime is 72972727. The reversal of 72972709 is 90727927.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39967684 + 33005025 = 6322^2 + 5745^2 .

It is a cyclic number.

It is not a de Polignac number, because 72972709 - 2¹ = 72972707 is a prime.

Together with 72972707, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72972701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36486354 + 36486355.

It is an arithmetic number, because the mean of its divisors is an integer number (36486355).

Almost surely, 2^72972709 is an apocalyptic number.

It is an amenable number.

72972709 is a deficient number, since it is larger than the sum of its proper divisors (1).

72972709 is an equidigital number, since it uses as much as digits as its factorization.

72972709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 111132, while the sum is 43.

The square root of 72972709 is about 8542.4065110483. The cubic root of 72972709 is about 417.8818317100.

The spelling of 72972709 in words is "seventy-two million, nine hundred seventy-two thousand, seven hundred nine".