81017249 has 2 divisors, whose sum is σ = 81017250. Its totient is φ = 81017248.

The previous prime is 81017243. The next prime is 81017263. The reversal of 81017249 is 94271018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61152400 + 19864849 = 7820^2 + 4457^2 .

It is a cyclic number.

It is not a de Polignac number, because 81017249 - 2²⁰ = 79968673 is a prime.

It is not a weakly prime, because it can be changed into another prime (81017243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40508624 + 40508625.

It is an arithmetic number, because the mean of its divisors is an integer number (40508625).

Almost surely, 2^81017249 is an apocalyptic number.

It is an amenable number.

81017249 is a deficient number, since it is larger than the sum of its proper divisors (1).

81017249 is an equidigital number, since it uses as much as digits as its factorization.

81017249 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 81017249 is about 9000.9582267667. The cubic root of 81017249 is about 432.7055817060.

The spelling of 81017249 in words is "eighty-one million, seventeen thousand, two hundred forty-nine".