81788245 has 16 divisors (see below), whose sum is σ = 122364288. Its totient is φ = 50984640.

The previous prime is 81788233. The next prime is 81788249. The reversal of 81788245 is 54288718.

It is not a de Polignac number, because 81788245 - 2¹¹ = 81786197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81788249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105834 + ... + 106603.

It is an arithmetic number, because the mean of its divisors is an integer number (7647768).

Almost surely, 2^81788245 is an apocalyptic number.

It is an amenable number.

81788245 is a deficient number, since it is larger than the sum of its proper divisors (40576043).

81788245 is a wasteful number, since it uses less digits than its factorization.

81788245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212460.

The product of its digits is 143360, while the sum is 43.

The square root of 81788245 is about 9043.6853660441. The cubic root of 81788245 is about 434.0738564164.

The spelling of 81788245 in words is "eighty-one million, seven hundred eighty-eight thousand, two hundred forty-five".