81684010 has 16 divisors (see below), whose sum is σ = 152101800. Its totient is φ = 31546816.

The previous prime is 81683999. The next prime is 81684011. The reversal of 81684010 is 1048618.

It can be written as a sum of positive squares in 4 ways, for example, as 43996689 + 37687321 = 6633^2 + 6139^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81684010.

It is not an unprimeable number, because it can be changed into a prime (81684011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 140545 + ... + 141124.

Almost surely, 2^81684010 is an apocalyptic number.

81684010 is a deficient number, since it is larger than the sum of its proper divisors (70417790).

81684010 is a wasteful number, since it uses less digits than its factorization.

81684010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281705.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 81684010 is about 9037.9206679413. The cubic root of 81684010 is about 433.8893762662.

The spelling of 81684010 in words is "eighty-one million, six hundred eighty-four thousand, ten".