81610 has 8 divisors (see below), whose sum is σ = 146916. Its totient is φ = 32640.

The previous prime is 81569. The next prime is 81611. The reversal of 81610 is 1618.

81610 = T₂₀₀ + T₂₀₁ + ... + T₂₀₃.

It can be written as a sum of positive squares in 2 ways, for example, as 80089 + 1521 = 283^2 + 39^2 .

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

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (81611) by changing a digit.

81610 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4071 + ... + 4090.

2⁸¹⁶¹⁰ is an apocalyptic number.

81610 is a deficient number, since it is larger than the sum of its proper divisors (65306).

81610 is a wasteful number, since it uses less digits than its factorization.

81610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8168.

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 81610 is about 285.6746401065. The cubic root of 81610 is about 43.3758294487.

It can be divided in two parts, 8 and 1610, that multiplied together give a triangular number (12880 = T₁₆₀).

The spelling of 81610 in words is "eighty-one thousand, six hundred ten".