72165571 has 2 divisors, whose sum is σ = 72165572. Its totient is φ = 72165570.

The previous prime is 72165563. The next prime is 72165581. The reversal of 72165571 is 17556127.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 72165571 - 2³ = 72165563 is a prime.

It is not a weakly prime, because it can be changed into another prime (72165581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36082785 + 36082786.

It is an arithmetic number, because the mean of its divisors is an integer number (36082786).

Almost surely, 2^72165571 is an apocalyptic number.

72165571 is a deficient number, since it is larger than the sum of its proper divisors (1).

72165571 is an equidigital number, since it uses as much as digits as its factorization.

72165571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14700, while the sum is 34.

The square root of 72165571 is about 8495.0321364901. The cubic root of 72165571 is about 416.3354108145.

The spelling of 72165571 in words is "seventy-two million, one hundred sixty-five thousand, five hundred seventy-one".