81503169 has 8 divisors (see below), whose sum is σ = 118550112. Its totient is φ = 49395840.

The previous prime is 81503159. The next prime is 81503173. The reversal of 81503169 is 96130518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81503169 - 2⁴ = 81503153 is a prime.

It is a super-2 number, since 2×81503169² = 13285533114085122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 2469793 = 81503169 / (8 + 1 + 5 + 0 + 3 + 1 + 6 + 9).

It is not an unprimeable number, because it can be changed into a prime (81503159) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1234864 + ... + 1234929.

It is an arithmetic number, because the mean of its divisors is an integer number (14818764).

Almost surely, 2^81503169 is an apocalyptic number.

It is an amenable number.

81503169 is a deficient number, since it is larger than the sum of its proper divisors (37046943).

81503169 is a wasteful number, since it uses less digits than its factorization.

81503169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2469807.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 81503169 is about 9027.9105556048. The cubic root of 81503169 is about 433.5689424187.

The spelling of 81503169 in words is "eighty-one million, five hundred three thousand, one hundred sixty-nine".