81670158 has 24 divisors (see below), whose sum is σ = 181068888. Its totient is φ = 26590032.

The previous prime is 81670153. The next prime is 81670187. The reversal of 81670158 is 85107618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81670153) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 51985 + ... + 53532.

It is an arithmetic number, because the mean of its divisors is an integer number (7544537).

Almost surely, 2^81670158 is an apocalyptic number.

81670158 is an abundant number, since it is smaller than the sum of its proper divisors (99398730).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81670158 is a wasteful number, since it uses less digits than its factorization.

81670158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105568 (or 105565 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 36.

The square root of 81670158 is about 9037.1543087412. The cubic root of 81670158 is about 433.8648485142.

The spelling of 81670158 in words is "eighty-one million, six hundred seventy thousand, one hundred fifty-eight".