81143735 has 4 divisors (see below), whose sum is σ = 97372488. Its totient is φ = 64914984.

The previous prime is 81143731. The next prime is 81143749. The reversal of 81143735 is 53734118.

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 81143735 - 2² = 81143731 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 (81143731) 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, 8114369 + ... + 8114378.

It is an arithmetic number, because the mean of its divisors is an integer number (24343122).

Almost surely, 2^81143735 is an apocalyptic number.

81143735 is a deficient number, since it is larger than the sum of its proper divisors (16228753).

81143735 is a wasteful number, since it uses less digits than its factorization.

81143735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16228752.

The product of its digits is 10080, while the sum is 32.

The square root of 81143735 is about 9007.9817384362. The cubic root of 81143735 is about 432.9306479358.

The spelling of 81143735 in words is "eighty-one million, one hundred forty-three thousand, seven hundred thirty-five".