81648279 has 6 divisors (see below), whose sum is σ = 117936416. Its totient is φ = 54432180.

The previous prime is 81648257. The next prime is 81648313. The reversal of 81648279 is 97284618.

It is not a de Polignac number, because 81648279 - 2⁹ = 81647767 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 (81643279) 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 5 ways as a sum of consecutive naturals, for example, 4536007 + ... + 4536024.

Almost surely, 2^81648279 is an apocalyptic number.

81648279 is a deficient number, since it is larger than the sum of its proper divisors (36288137).

81648279 is a wasteful number, since it uses less digits than its factorization.

81648279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9072037 (or 9072034 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 81648279 is about 9035.9437249244. The cubic root of 81648279 is about 433.8261016939.

The spelling of 81648279 in words is "eighty-one million, six hundred forty-eight thousand, two hundred seventy-nine".