81742538 has 8 divisors (see below), whose sum is σ = 122661540. Its totient is φ = 40855360.

The previous prime is 81742537. The next prime is 81742547. The reversal of 81742538 is 83524718.

It can be written as a sum of positive squares in 2 ways, for example, as 81234169 + 508369 = 9013^2 + 713^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (81742537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98 + ... + 12786.

Almost surely, 2^81742538 is an apocalyptic number.

81742538 is a deficient number, since it is larger than the sum of its proper divisors (40919002).

81742538 is a wasteful number, since it uses less digits than its factorization.

81742538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15912.

The product of its digits is 53760, while the sum is 38.

The square root of 81742538 is about 9041.1580010527. The cubic root of 81742538 is about 433.9929812622.

The spelling of 81742538 in words is "eighty-one million, seven hundred forty-two thousand, five hundred thirty-eight".