81450073 has 2 divisors, whose sum is σ = 81450074. Its totient is φ = 81450072.

The previous prime is 81450071. The next prime is 81450119. The reversal of 81450073 is 37005418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49674304 + 31775769 = 7048^2 + 5637^2 .

It is a cyclic number.

It is not a de Polignac number, because 81450073 - 2¹ = 81450071 is a prime.

It is a super-2 number, since 2×81450073² = 13268228783410658, which contains 22 as substring.

Together with 81450071, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (81450071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40725036 + 40725037.

It is an arithmetic number, because the mean of its divisors is an integer number (40725037).

Almost surely, 2^81450073 is an apocalyptic number.

It is an amenable number.

81450073 is a deficient number, since it is larger than the sum of its proper divisors (1).

81450073 is an equidigital number, since it uses as much as digits as its factorization.

81450073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 81450073 is about 9024.9694182307. The cubic root of 81450073 is about 433.4747711217.

The spelling of 81450073 in words is "eighty-one million, four hundred fifty thousand, seventy-three".