81865935 has 24 divisors (see below), whose sum is σ = 142784304. Its totient is φ = 43390080.

The previous prime is 81865933. The next prime is 81865939. The reversal of 81865935 is 53956818.

It is not a de Polignac number, because 81865935 - 2¹ = 81865933 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81865933) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1755 + ... + 12915.

It is an arithmetic number, because the mean of its divisors is an integer number (5949346).

Almost surely, 2^81865935 is an apocalyptic number.

81865935 is a deficient number, since it is larger than the sum of its proper divisors (60918369).

81865935 is a wasteful number, since it uses less digits than its factorization.

81865935 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11335 (or 11332 counting only the distinct ones).

The product of its digits is 259200, while the sum is 45.

The square root of 81865935 is about 9047.9796087303. The cubic root of 81865935 is about 434.2112540165.

The spelling of 81865935 in words is "eighty-one million, eight hundred sixty-five thousand, nine hundred thirty-five".