72021601 has 2 divisors, whose sum is σ = 72021602. Its totient is φ = 72021600.

The previous prime is 72021577. The next prime is 72021623. The reversal of 72021601 is 10612027.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61465600 + 10556001 = 7840^2 + 3249^2 .

It is an emirp because it is prime and its reverse (10612027) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72021601 - 2⁷ = 72021473 is a prime.

It is a super-2 number, since 2×72021601² = 10374222021206402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (72021661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36010800 + 36010801.

It is an arithmetic number, because the mean of its divisors is an integer number (36010801).

Almost surely, 2^72021601 is an apocalyptic number.

It is an amenable number.

72021601 is a deficient number, since it is larger than the sum of its proper divisors (1).

72021601 is an equidigital number, since it uses as much as digits as its factorization.

72021601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 72021601 is about 8486.5541299163. The cubic root of 72021601 is about 416.0583640530.

Adding to 72021601 its reverse (10612027), we get a palindrome (82633628).

The spelling of 72021601 in words is "seventy-two million, twenty-one thousand, six hundred one".