81186648 has 16 divisors (see below), whose sum is σ = 202966680. Its totient is φ = 27062208.

The previous prime is 81186643. The next prime is 81186653. The reversal of 81186648 is 84668118.

It is an interprime number because it is at equal distance from previous prime (81186643) and next prime (81186653).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81186643) 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, 1691365 + ... + 1691412.

Almost surely, 2^81186648 is an apocalyptic number.

It is an amenable number.

81186648 is an abundant number, since it is smaller than the sum of its proper divisors (121780032).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81186648 is a wasteful number, since it uses less digits than its factorization.

81186648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3382786 (or 3382782 counting only the distinct ones).

The product of its digits is 73728, while the sum is 42.

The square root of 81186648 is about 9010.3633667017. The cubic root of 81186648 is about 433.0069531852.

The spelling of 81186648 in words is "eighty-one million, one hundred eighty-six thousand, six hundred forty-eight".