81600073 has 2 divisors, whose sum is σ = 81600074. Its totient is φ = 81600072.

The previous prime is 81600053. The next prime is 81600137. The reversal of 81600073 is 37000618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62520649 + 19079424 = 7907^2 + 4368^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81600073 is a prime.

It is not a weakly prime, because it can be changed into another prime (81600023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40800036 + 40800037.

It is an arithmetic number, because the mean of its divisors is an integer number (40800037).

Almost surely, 2^81600073 is an apocalyptic number.

It is an amenable number.

81600073 is a deficient number, since it is larger than the sum of its proper divisors (1).

81600073 is an equidigital number, since it uses as much as digits as its factorization.

81600073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 81600073 is about 9033.2758731260. The cubic root of 81600073 is about 433.7407063926.

The spelling of 81600073 in words is "eighty-one million, six hundred thousand, seventy-three".