81652519 has 24 divisors (see below), whose sum is σ = 94867200. Its totient is φ = 70031520.

The previous prime is 81652517. The next prime is 81652523. The reversal of 81652519 is 91525618.

It is not a de Polignac number, because 81652519 - 2¹ = 81652517 is a prime.

It is a super-2 number, since 2×81652519² = 13334267718090722, 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 (81652517) 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 23 ways as a sum of consecutive naturals, for example, 189234 + ... + 189664.

It is an arithmetic number, because the mean of its divisors is an integer number (3952800).

Almost surely, 2^81652519 is an apocalyptic number.

81652519 is a deficient number, since it is larger than the sum of its proper divisors (13214681).

81652519 is a wasteful number, since it uses less digits than its factorization.

81652519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535 (or 522 counting only the distinct ones).

The product of its digits is 21600, while the sum is 37.

The square root of 81652519 is about 9036.1783404269. The cubic root of 81652519 is about 433.8336111024.

It can be divided in two parts, 816 and 52519, that added together give a palindrome (53335).

The spelling of 81652519 in words is "eighty-one million, six hundred fifty-two thousand, five hundred nineteen".