81681148 has 6 divisors (see below), whose sum is σ = 142942016. Its totient is φ = 40840572.

The previous prime is 81681121. The next prime is 81681167. The reversal of 81681148 is 84118618.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10210140 + ... + 10210147.

Almost surely, 2^81681148 is an apocalyptic number.

It is an amenable number.

81681148 is a deficient number, since it is larger than the sum of its proper divisors (61260868).

81681148 is a wasteful number, since it uses less digits than its factorization.

81681148 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20420291 (or 20420289 counting only the distinct ones).

The product of its digits is 12288, while the sum is 37.

The square root of 81681148 is about 9037.7623336753. The cubic root of 81681148 is about 433.8843087469.

It can be divided in two parts, 8168 and 1148, that added together give a triangular number (9316 = T₁₃₆).

The spelling of 81681148 in words is "eighty-one million, six hundred eighty-one thousand, one hundred forty-eight".