81120079 has 2 divisors, whose sum is σ = 81120080. Its totient is φ = 81120078.

The previous prime is 81120071. The next prime is 81120113. The reversal of 81120079 is 97002118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81120079 - 2³ = 81120071 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81120071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40560039 + 40560040.

It is an arithmetic number, because the mean of its divisors is an integer number (40560040).

Almost surely, 2^81120079 is an apocalyptic number.

81120079 is a deficient number, since it is larger than the sum of its proper divisors (1).

81120079 is an equidigital number, since it uses as much as digits as its factorization.

81120079 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 81120079 is about 9006.6685849986. The cubic root of 81120079 is about 432.8885727927. Note that the first 3 decimals are identical.

The spelling of 81120079 in words is "eighty-one million, one hundred twenty thousand, seventy-nine".