72705173 has 2 divisors, whose sum is σ = 72705174. Its totient is φ = 72705172.

The previous prime is 72705167. The next prime is 72705181. The reversal of 72705173 is 37150727.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55249489 + 17455684 = 7433^2 + 4178^2 .

It is a cyclic number.

It is not a de Polignac number, because 72705173 - 2⁸ = 72704917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72705103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36352586 + 36352587.

It is an arithmetic number, because the mean of its divisors is an integer number (36352587).

Almost surely, 2^72705173 is an apocalyptic number.

It is an amenable number.

72705173 is a deficient number, since it is larger than the sum of its proper divisors (1).

72705173 is an equidigital number, since it uses as much as digits as its factorization.

72705173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10290, while the sum is 32.

The square root of 72705173 is about 8526.7328444135. The cubic root of 72705173 is about 417.3705202845.

The spelling of 72705173 in words is "seventy-two million, seven hundred five thousand, one hundred seventy-three".