81518148 has 18 divisors (see below), whose sum is σ = 206059854. Its totient is φ = 27172704.

The previous prime is 81518147. The next prime is 81518149. The reversal of 81518148 is 84181518.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81518147) and next prime (81518149).

It can be written as a sum of positive squares in only one way, i.e., 80245764 + 1272384 = 8958^2 + 1128^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 2264393 = 81518148 / (8 + 1 + 5 + 1 + 8 + 1 + 4 + 8).

It is not an unprimeable number, because it can be changed into a prime (81518147) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1132161 + ... + 1132232.

Almost surely, 2^81518148 is an apocalyptic number.

It is an amenable number.

81518148 is an abundant number, since it is smaller than the sum of its proper divisors (124541706).

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

81518148 is a wasteful number, since it uses less digits than its factorization.

81518148 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2264403 (or 2264398 counting only the distinct ones).

The product of its digits is 10240, while the sum is 36.

The square root of 81518148 is about 9028.7401114441. The cubic root of 81518148 is about 433.5955018415.

The spelling of 81518148 in words is "eighty-one million, five hundred eighteen thousand, one hundred forty-eight".