81740885 has 8 divisors (see below), whose sum is σ = 98220600. Its totient is φ = 65305024.

The previous prime is 81740861. The next prime is 81740891. The reversal of 81740885 is 58804718.

It can be written as a sum of positive squares in 4 ways, for example, as 2477476 + 79263409 = 1574^2 + 8903^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 81740885 - 2¹² = 81736789 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6710 + ... + 14439.

It is an arithmetic number, because the mean of its divisors is an integer number (12277575).

Almost surely, 2^81740885 is an apocalyptic number.

It is an amenable number.

81740885 is a deficient number, since it is larger than the sum of its proper divisors (16479715).

81740885 is a wasteful number, since it uses less digits than its factorization.

81740885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21927.

The product of its (nonzero) digits is 71680, while the sum is 41.

The square root of 81740885 is about 9041.0665853095. The cubic root of 81740885 is about 433.9900558362.

The spelling of 81740885 in words is "eighty-one million, seven hundred forty thousand, eight hundred eighty-five".