81684501 has 8 divisors (see below), whose sum is σ = 110967840. Its totient is φ = 53428752.

The previous prime is 81684481. The next prime is 81684509. The reversal of 81684501 is 10548618.

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

It is not a de Polignac number, because 81684501 - 2⁶ = 81684437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81684509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 256711 + ... + 257028.

It is an arithmetic number, because the mean of its divisors is an integer number (13870980).

Almost surely, 2^81684501 is an apocalyptic number.

It is an amenable number.

81684501 is a deficient number, since it is larger than the sum of its proper divisors (29283339).

81684501 is a wasteful number, since it uses less digits than its factorization.

81684501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513795.

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 81684501 is about 9037.9478312281. The cubic root of 81684501 is about 433.8902456296.

The spelling of 81684501 in words is "eighty-one million, six hundred eighty-four thousand, five hundred one".