81536785 has 8 divisors (see below), whose sum is σ = 106739136. Its totient is φ = 59299440.

The previous prime is 81536773. The next prime is 81536797. The reversal of 81536785 is 58763518.

It is an interprime number because it is at equal distance from previous prime (81536773) and next prime (81536797).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81536785 - 2⁵ = 81536753 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 741189 + ... + 741298.

It is an arithmetic number, because the mean of its divisors is an integer number (13342392).

Almost surely, 2^81536785 is an apocalyptic number.

It is an amenable number.

81536785 is a deficient number, since it is larger than the sum of its proper divisors (25202351).

81536785 is a wasteful number, since it uses less digits than its factorization.

81536785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1482503.

The product of its digits is 201600, while the sum is 43.

The square root of 81536785 is about 9029.7721455195. The cubic root of 81536785 is about 433.6285427606.

The spelling of 81536785 in words is "eighty-one million, five hundred thirty-six thousand, seven hundred eighty-five".