81145144 has 16 divisors (see below), whose sum is σ = 156259800. Its totient is φ = 39475872.

The previous prime is 81145139. The next prime is 81145147. The reversal of 81145144 is 44154118.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81145147) 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 3 ways as a sum of consecutive naturals, for example, 136774 + ... + 137365.

Almost surely, 2^81145144 is an apocalyptic number.

It is an amenable number.

81145144 is a deficient number, since it is larger than the sum of its proper divisors (75114656).

81145144 is a wasteful number, since it uses less digits than its factorization.

81145144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274182 (or 274178 counting only the distinct ones).

The product of its digits is 2560, while the sum is 28.

The square root of 81145144 is about 9008.0599465146. The cubic root of 81145144 is about 432.9331537598.

The spelling of 81145144 in words is "eighty-one million, one hundred forty-five thousand, one hundred forty-four".