81755493 has 4 divisors (see below), whose sum is σ = 109007328. Its totient is φ = 54503660.

The previous prime is 81755483. The next prime is 81755503. The reversal of 81755493 is 39455718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (81755483) and next prime (81755503).

It is a cyclic number.

It is not a de Polignac number, because 81755493 - 2¹⁶ = 81689957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81755413) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13625913 + ... + 13625918.

It is an arithmetic number, because the mean of its divisors is an integer number (27251832).

Almost surely, 2^81755493 is an apocalyptic number.

It is an amenable number.

81755493 is a deficient number, since it is larger than the sum of its proper divisors (27251835).

81755493 is a wasteful number, since it uses less digits than its factorization.

81755493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27251834.

The product of its digits is 151200, while the sum is 42.

The square root of 81755493 is about 9041.8744185042. The cubic root of 81755493 is about 434.0159072369.

The spelling of 81755493 in words is "eighty-one million, seven hundred fifty-five thousand, four hundred ninety-three".