81753491 has 2 divisors, whose sum is σ = 81753492. Its totient is φ = 81753490.

The previous prime is 81753473. The next prime is 81753521. The reversal of 81753491 is 19435718.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81753491 - 2¹⁰ = 81752467 is a prime.

It is not a weakly prime, because it can be changed into another prime (81753691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40876745 + 40876746.

It is an arithmetic number, because the mean of its divisors is an integer number (40876746).

Almost surely, 2^81753491 is an apocalyptic number.

81753491 is a deficient number, since it is larger than the sum of its proper divisors (1).

81753491 is an equidigital number, since it uses as much as digits as its factorization.

81753491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 38.

The square root of 81753491 is about 9041.7637106927. The cubic root of 81753491 is about 434.0123645313.

The spelling of 81753491 in words is "eighty-one million, seven hundred fifty-three thousand, four hundred ninety-one".