81057670 has 16 divisors (see below), whose sum is σ = 148657680. Its totient is φ = 31811104.

The previous prime is 81057661. The next prime is 81057673. The reversal of 81057670 is 7675018.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81057673) 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, 75940 + ... + 76999.

It is an arithmetic number, because the mean of its divisors is an integer number (9291105).

Almost surely, 2^81057670 is an apocalyptic number.

81057670 is a deficient number, since it is larger than the sum of its proper divisors (67600010).

81057670 is a wasteful number, since it uses less digits than its factorization.

81057670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152999.

The product of its (nonzero) digits is 11760, while the sum is 34.

The square root of 81057670 is about 9003.2033188194. The cubic root of 81057670 is about 432.7775313405. Note that the first 3 decimals are identical.

The spelling of 81057670 in words is "eighty-one million, fifty-seven thousand, six hundred seventy".