81735749 has 2 divisors, whose sum is σ = 81735750. Its totient is φ = 81735748.

The previous prime is 81735727. The next prime is 81735757. The reversal of 81735749 is 94753718.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73839649 + 7896100 = 8593^2 + 2810^2 .

It is a cyclic number.

It is not a de Polignac number, because 81735749 - 2²⁴ = 64958533 is a prime.

It is a super-3 number, since 3×81735749³ (a number of 25 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81735149) 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, 40867874 + 40867875.

It is an arithmetic number, because the mean of its divisors is an integer number (40867875).

Almost surely, 2^81735749 is an apocalyptic number.

It is an amenable number.

81735749 is a deficient number, since it is larger than the sum of its proper divisors (1).

81735749 is an equidigital number, since it uses as much as digits as its factorization.

81735749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 211680, while the sum is 44.

The square root of 81735749 is about 9040.7825435634. The cubic root of 81735749 is about 433.9809660577.

The spelling of 81735749 in words is "eighty-one million, seven hundred thirty-five thousand, seven hundred forty-nine".