81945258 has 8 divisors (see below), whose sum is σ = 163890528. Its totient is φ = 27315084.

The previous prime is 81945191. The next prime is 81945263. The reversal of 81945258 is 85254918.

It is a happy number.

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

81945258 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6828766 + ... + 6828777.

It is an arithmetic number, because the mean of its divisors is an integer number (20486316).

Almost surely, 2^81945258 is an apocalyptic number.

81945258 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81945258 is a wasteful number, since it uses less digits than its factorization.

81945258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13657548.

The product of its digits is 115200, while the sum is 42.

The square root of 81945258 is about 9052.3620122043. The cubic root of 81945258 is about 434.3514499801.

The spelling of 81945258 in words is "eighty-one million, nine hundred forty-five thousand, two hundred fifty-eight".