81753871 has 4 divisors (see below), whose sum is σ = 84573000. Its totient is φ = 78934744.

The previous prime is 81753863. The next prime is 81753911. The reversal of 81753871 is 17835718.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81753871 - 2³ = 81753863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81753811) 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, 1409521 + ... + 1409578.

It is an arithmetic number, because the mean of its divisors is an integer number (21143250).

Almost surely, 2^81753871 is an apocalyptic number.

81753871 is a deficient number, since it is larger than the sum of its proper divisors (2819129).

81753871 is a wasteful number, since it uses less digits than its factorization.

81753871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2819128.

The product of its digits is 47040, while the sum is 40.

The square root of 81753871 is about 9041.7847242677. The cubic root of 81753871 is about 434.0130369773.

The spelling of 81753871 in words is "eighty-one million, seven hundred fifty-three thousand, eight hundred seventy-one".