81029513 has 2 divisors, whose sum is σ = 81029514. Its totient is φ = 81029512.

The previous prime is 81029491. The next prime is 81029521. The reversal of 81029513 is 31592018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55547209 + 25482304 = 7453^2 + 5048^2 .

It is a cyclic number.

It is not a de Polignac number, because 81029513 - 2¹⁰ = 81028489 is a prime.

It is not a weakly prime, because it can be changed into another prime (81029213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40514756 + 40514757.

It is an arithmetic number, because the mean of its divisors is an integer number (40514757).

Almost surely, 2^81029513 is an apocalyptic number.

It is an amenable number.

81029513 is a deficient number, since it is larger than the sum of its proper divisors (1).

81029513 is an equidigital number, since it uses as much as digits as its factorization.

81029513 is an evil number, because the sum of its binary digits is even.

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

The square root of 81029513 is about 9001.6394617869. The cubic root of 81029513 is about 432.7274142317.

The spelling of 81029513 in words is "eighty-one million, twenty-nine thousand, five hundred thirteen".