81351711 has 72 divisors (see below), whose sum is σ = 146608800. Its totient is φ = 43436736.

The previous prime is 81351701. The next prime is 81351733. The reversal of 81351711 is 11715318.

It is not a de Polignac number, because 81351711 - 2⁵ = 81351679 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81351701) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1114371 + ... + 1114443.

Almost surely, 2^81351711 is an apocalyptic number.

81351711 is a deficient number, since it is larger than the sum of its proper divisors (65257089).

81351711 is a wasteful number, since it uses less digits than its factorization.

81351711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138 (or 102 counting only the distinct ones).

The product of its digits is 840, while the sum is 27.

The square root of 81351711 is about 9019.5183352549. The cubic root of 81351711 is about 433.3002076585.

The spelling of 81351711 in words is "eighty-one million, three hundred fifty-one thousand, seven hundred eleven".