81568379 has 2 divisors, whose sum is σ = 81568380. Its totient is φ = 81568378.

The previous prime is 81568351. The next prime is 81568381. The reversal of 81568379 is 97386518.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81568379 - 2¹⁶ = 81502843 is a prime.

Together with 81568381, it forms a pair of twin primes.

It is a Chen prime.

It is a pancake number, because a pancake can be divided into 81568379 parts by 12772 straight cuts.

It is not a weakly prime, because it can be changed into another prime (81568339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40784189 + 40784190.

It is an arithmetic number, because the mean of its divisors is an integer number (40784190).

Almost surely, 2^81568379 is an apocalyptic number.

81568379 is a deficient number, since it is larger than the sum of its proper divisors (1).

81568379 is an equidigital number, since it uses as much as digits as its factorization.

81568379 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 47.

The square root of 81568379 is about 9031.5214111466. The cubic root of 81568379 is about 433.6845432151.

The spelling of 81568379 in words is "eighty-one million, five hundred sixty-eight thousand, three hundred seventy-nine".