72001649 has 2 divisors, whose sum is σ = 72001650. Its totient is φ = 72001648.

The previous prime is 72001639. The next prime is 72001663. The reversal of 72001649 is 94610027.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63043600 + 8958049 = 7940^2 + 2993^2 .

It is an emirp because it is prime and its reverse (94610027) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72001649 - 2¹² = 71997553 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72001639) 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, 36000824 + 36000825.

It is an arithmetic number, because the mean of its divisors is an integer number (36000825).

Almost surely, 2^72001649 is an apocalyptic number.

It is an amenable number.

72001649 is a deficient number, since it is larger than the sum of its proper divisors (1).

72001649 is an equidigital number, since it uses as much as digits as its factorization.

72001649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 72001649 is about 8485.3785419391. The cubic root of 72001649 is about 416.0199405660.

The spelling of 72001649 in words is "seventy-two million, one thousand, six hundred forty-nine".