81079501 has 2 divisors, whose sum is σ = 81079502. Its totient is φ = 81079500.

The previous prime is 81079499. The next prime is 81079513. The reversal of 81079501 is 10597018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63186601 + 17892900 = 7949^2 + 4230^2 .

It is a cyclic number.

It is not a de Polignac number, because 81079501 - 2¹ = 81079499 is a prime.

Together with 81079499, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81073501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40539750 + 40539751.

It is an arithmetic number, because the mean of its divisors is an integer number (40539751).

Almost surely, 2^81079501 is an apocalyptic number.

It is an amenable number.

81079501 is a deficient number, since it is larger than the sum of its proper divisors (1).

81079501 is an equidigital number, since it uses as much as digits as its factorization.

81079501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 31.

The square root of 81079501 is about 9004.4156390073. The cubic root of 81079501 is about 432.8163807104.

The spelling of 81079501 in words is "eighty-one million, seventy-nine thousand, five hundred one".