81662799 has 8 divisors (see below), whose sum is σ = 108978352. Its totient is φ = 54394560.

The previous prime is 81662767. The next prime is 81662821. The reversal of 81662799 is 99726618.

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

It is not a de Polignac number, because 81662799 - 2⁵ = 81662767 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 (81662729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7582 + ... + 14859.

It is an arithmetic number, because the mean of its divisors is an integer number (13622294).

Almost surely, 2^81662799 is an apocalyptic number.

81662799 is a deficient number, since it is larger than the sum of its proper divisors (27315553).

81662799 is a wasteful number, since it uses less digits than its factorization.

81662799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23657.

The product of its digits is 326592, while the sum is 48.

The square root of 81662799 is about 9036.7471470657. The cubic root of 81662799 is about 433.8518167966.

The spelling of 81662799 in words is "eighty-one million, six hundred sixty-two thousand, seven hundred ninety-nine".