81279297 has 12 divisors (see below), whose sum is σ = 128076624. Its totient is φ = 49260120.

The previous prime is 81279287. The next prime is 81279301. The reversal of 81279297 is 79297218.

It is not a de Polignac number, because 81279297 - 2⁴ = 81279281 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81279287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 410403 + ... + 410600.

It is an arithmetic number, because the mean of its divisors is an integer number (10673052).

Almost surely, 2^81279297 is an apocalyptic number.

It is an amenable number.

81279297 is a deficient number, since it is larger than the sum of its proper divisors (46797327).

81279297 is a wasteful number, since it uses less digits than its factorization.

81279297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 821020 (or 821017 counting only the distinct ones).

The product of its digits is 127008, while the sum is 45.

The square root of 81279297 is about 9015.5031473568. The cubic root of 81279297 is about 433.1716042754.

It can be divided in two parts, 8127 and 9297, that added together give a square (17424 = 132²).

The spelling of 81279297 in words is "eighty-one million, two hundred seventy-nine thousand, two hundred ninety-seven".