81318741 has 16 divisors (see below), whose sum is σ = 124136064. Its totient is φ = 46384704.

The previous prime is 81318709. The next prime is 81318779. The reversal of 81318741 is 14781318.

It is not a de Polignac number, because 81318741 - 2⁵ = 81318709 is a prime.

It is a super-2 number, since 2×81318741² = 13225475275650162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81318781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9715 + ... + 16031.

It is an arithmetic number, because the mean of its divisors is an integer number (7758504).

Almost surely, 2^81318741 is an apocalyptic number.

It is an amenable number.

81318741 is a deficient number, since it is larger than the sum of its proper divisors (42817323).

81318741 is a wasteful number, since it uses less digits than its factorization.

81318741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6940.

The product of its digits is 5376, while the sum is 33.

The square root of 81318741 is about 9017.6904471156. The cubic root of 81318741 is about 433.2416641727.

The spelling of 81318741 in words is "eighty-one million, three hundred eighteen thousand, seven hundred forty-one".