81503145 has 32 divisors (see below), whose sum is σ = 151200000. Its totient is φ = 41576832.

The previous prime is 81503057. The next prime is 81503153. The reversal of 81503145 is 54130518.

It is not a de Polignac number, because 81503145 - 2⁹ = 81502633 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10020 + ... + 16229.

It is an arithmetic number, because the mean of its divisors is an integer number (4725000).

Almost surely, 2^81503145 is an apocalyptic number.

It is an amenable number.

81503145 is a deficient number, since it is larger than the sum of its proper divisors (69696855).

81503145 is a wasteful number, since it uses less digits than its factorization.

81503145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26286 (or 26280 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 81503145 is about 9027.9092263935. The cubic root of 81503145 is about 433.5688998614.

The spelling of 81503145 in words is "eighty-one million, five hundred three thousand, one hundred forty-five".