81046513 has 2 divisors, whose sum is σ = 81046514. Its totient is φ = 81046512.

The previous prime is 81046501. The next prime is 81046517. The reversal of 81046513 is 31564018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80138304 + 908209 = 8952^2 + 953^2 .

It is a cyclic number.

It is not a de Polignac number, because 81046513 - 2¹⁷ = 80915441 is a prime.

It is equal to p_4727017 and since 81046513 and 4727017 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (81046517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40523256 + 40523257.

It is an arithmetic number, because the mean of its divisors is an integer number (40523257).

Almost surely, 2^81046513 is an apocalyptic number.

It is an amenable number.

81046513 is a deficient number, since it is larger than the sum of its proper divisors (1).

81046513 is an equidigital number, since it uses as much as digits as its factorization.

81046513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 81046513 is about 9002.5836846985. The cubic root of 81046513 is about 432.7576742007.

The spelling of 81046513 in words is "eighty-one million, forty-six thousand, five hundred thirteen".