81236386 has 64 divisors (see below), whose sum is σ = 159563520. Its totient is φ = 30101760.

The previous prime is 81236383. The next prime is 81236413. The reversal of 81236386 is 68363218.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is not an unprimeable number, because it can be changed into a prime (81236383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 301860 + ... + 302128.

It is an arithmetic number, because the mean of its divisors is an integer number (2493180).

Almost surely, 2^81236386 is an apocalyptic number.

81236386 is a deficient number, since it is larger than the sum of its proper divisors (78327134).

81236386 is a wasteful number, since it uses less digits than its factorization.

81236386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379.

The product of its digits is 41472, while the sum is 37.

The square root of 81236386 is about 9013.1229881767. The cubic root of 81236386 is about 433.0953605927.

The spelling of 81236386 in words is "eighty-one million, two hundred thirty-six thousand, three hundred eighty-six".