81700369 has 2 divisors, whose sum is σ = 81700370. Its totient is φ = 81700368.

The previous prime is 81700343. The next prime is 81700417. The reversal of 81700369 is 96300718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78854400 + 2845969 = 8880^2 + 1687^2 .

It is a cyclic number.

It is not a de Polignac number, because 81700369 - 2⁹ = 81699857 is a prime.

It is a super-2 number, since 2×81700369² = 13349900589472322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81707369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40850184 + 40850185.

It is an arithmetic number, because the mean of its divisors is an integer number (40850185).

Almost surely, 2^81700369 is an apocalyptic number.

It is an amenable number.

81700369 is a deficient number, since it is larger than the sum of its proper divisors (1).

81700369 is an equidigital number, since it uses as much as digits as its factorization.

81700369 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 81700369 is about 9038.8256427481. The cubic root of 81700369 is about 433.9183395950.

The spelling of 81700369 in words is "eighty-one million, seven hundred thousand, three hundred sixty-nine".