81073397 has 2 divisors, whose sum is σ = 81073398. Its totient is φ = 81073396.

The previous prime is 81073381. The next prime is 81073403. The reversal of 81073397 is 79337018.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80442961 + 630436 = 8969^2 + 794^2 .

It is a cyclic number.

It is not a de Polignac number, because 81073397 - 2⁴ = 81073381 is a prime.

It is a super-2 number, since 2×81073397² = 13145791402239218, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81073397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81073337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40536698 + 40536699.

It is an arithmetic number, because the mean of its divisors is an integer number (40536699).

Almost surely, 2^81073397 is an apocalyptic number.

It is an amenable number.

81073397 is a deficient number, since it is larger than the sum of its proper divisors (1).

81073397 is an equidigital number, since it uses as much as digits as its factorization.

81073397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31752, while the sum is 38.

The square root of 81073397 is about 9004.0766878120. The cubic root of 81073397 is about 432.8055190357.

The spelling of 81073397 in words is "eighty-one million, seventy-three thousand, three hundred ninety-seven".