81663526 has 8 divisors (see below), whose sum is σ = 139994640. Its totient is φ = 34998648.

The previous prime is 81663503. The next prime is 81663587. The reversal of 81663526 is 62536618.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2916541 + ... + 2916568.

It is an arithmetic number, because the mean of its divisors is an integer number (17499330).

Almost surely, 2^81663526 is an apocalyptic number.

81663526 is a deficient number, since it is larger than the sum of its proper divisors (58331114).

81663526 is a wasteful number, since it uses less digits than its factorization.

81663526 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5833118.

The product of its digits is 51840, while the sum is 37.

The square root of 81663526 is about 9036.7873716272. The cubic root of 81663526 is about 433.8531042426.

The spelling of 81663526 in words is "eighty-one million, six hundred sixty-three thousand, five hundred twenty-six".