81015293 has 2 divisors, whose sum is σ = 81015294. Its totient is φ = 81015292.

The previous prime is 81015289. The next prime is 81015313. The reversal of 81015293 is 39251018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55995289 + 25020004 = 7483^2 + 5002^2 .

It is a cyclic number.

It is not a de Polignac number, because 81015293 - 2² = 81015289 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81015793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40507646 + 40507647.

It is an arithmetic number, because the mean of its divisors is an integer number (40507647).

Almost surely, 2^81015293 is an apocalyptic number.

It is an amenable number.

81015293 is a deficient number, since it is larger than the sum of its proper divisors (1).

81015293 is an equidigital number, since it uses as much as digits as its factorization.

81015293 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 81015293 is about 9000.8495710127. The cubic root of 81015293 is about 432.7020994067.

The spelling of 81015293 in words is "eighty-one million, fifteen thousand, two hundred ninety-three".