81503197 has 4 divisors (see below), whose sum is σ = 81529756. Its totient is φ = 81476640.

The previous prime is 81503173. The next prime is 81503209. The reversal of 81503197 is 79130518.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38613796 + 42889401 = 6214^2 + 6549^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81503197 is a prime.

It is a super-2 number, since 2×81503197² = 13285542242441618, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81503497) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 7968 + ... + 15049.

It is an arithmetic number, because the mean of its divisors is an integer number (20382439).

Almost surely, 2^81503197 is an apocalyptic number.

It is an amenable number.

81503197 is a deficient number, since it is larger than the sum of its proper divisors (26559).

81503197 is a wasteful number, since it uses less digits than its factorization.

81503197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26558.

The product of its (nonzero) digits is 7560, while the sum is 34.

The square root of 81503197 is about 9027.9121063511. The cubic root of 81503197 is about 433.5689920688.

The spelling of 81503197 in words is "eighty-one million, five hundred three thousand, one hundred ninety-seven".