81542711 has 2 divisors, whose sum is σ = 81542712. Its totient is φ = 81542710.

The previous prime is 81542707. The next prime is 81542753. The reversal of 81542711 is 11724518.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81542711 - 2² = 81542707 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81542011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40771355 + 40771356.

It is an arithmetic number, because the mean of its divisors is an integer number (40771356).

Almost surely, 2^81542711 is an apocalyptic number.

81542711 is a deficient number, since it is larger than the sum of its proper divisors (1).

81542711 is an equidigital number, since it uses as much as digits as its factorization.

81542711 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2240, while the sum is 29.

The square root of 81542711 is about 9030.1002762982. The cubic root of 81542711 is about 433.6390477145.

The spelling of 81542711 in words is "eighty-one million, five hundred forty-two thousand, seven hundred eleven".