81049663 has 4 divisors (see below), whose sum is σ = 82378408. Its totient is φ = 79720920.

The previous prime is 81049621. The next prime is 81049679. The reversal of 81049663 is 36694018.

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

It is a cyclic number.

It is not a de Polignac number, because 81049663 - 2⁹ = 81049151 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 (81349663) 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, 664281 + ... + 664402.

It is an arithmetic number, because the mean of its divisors is an integer number (20594602).

Almost surely, 2^81049663 is an apocalyptic number.

81049663 is a deficient number, since it is larger than the sum of its proper divisors (1328745).

81049663 is a wasteful number, since it uses less digits than its factorization.

81049663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1328744.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 81049663 is about 9002.7586327747. The cubic root of 81049663 is about 432.7632807302.

The spelling of 81049663 in words is "eighty-one million, forty-nine thousand, six hundred sixty-three".