81630503 has 4 divisors (see below), whose sum is σ = 81718560. Its totient is φ = 81542448.

The previous prime is 81630433. The next prime is 81630509. The reversal of 81630503 is 30503618.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30503618 = 2 ⋅15251809.

It is a cyclic number.

It is not a de Polignac number, because 81630503 - 2⁸ = 81630247 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81630509) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42623 + ... + 44496.

It is an arithmetic number, because the mean of its divisors is an integer number (20429640).

Almost surely, 2^81630503 is an apocalyptic number.

81630503 is a deficient number, since it is larger than the sum of its proper divisors (88057).

81630503 is an equidigital number, since it uses as much as digits as its factorization.

81630503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88056.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 81630503 is about 9034.9600441839. The cubic root of 81630503 is about 433.7946160231.

The spelling of 81630503 in words is "eighty-one million, six hundred thirty thousand, five hundred three".