81970 has 16 divisors (see below), whose sum is σ = 168768. Its totient is φ = 28080.

The previous prime is 81967. The next prime is 81971. The reversal of 81970 is 7918.

81970 = 40² + 41² + ... + 67².

It is not an unprimeable number, because it can be changed into a prime (81971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 516 + ... + 655.

It is an arithmetic number, because the mean of its divisors is an integer number (10548).

2⁸¹⁹⁷⁰ is an apocalyptic number.

81970 is an abundant number, since it is smaller than the sum of its proper divisors (86798).

It is a weird number, because it is abundant, but not a pseudoperfect number.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84384).

81970 is a wasteful number, since it uses less digits than its factorization.

81970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1185.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 81970 is about 286.3040342014. The cubic root of 81970 is about 43.4395160633.

The spelling of 81970 in words is "eighty-one thousand, nine hundred seventy".