81857946 has 16 divisors (see below), whose sum is σ = 163826208. Its totient is φ = 27267600.

The previous prime is 81857899. The next prime is 81858013. The reversal of 81857946 is 64975818.

It is a junction number, because it is equal to n+sod(n) for n = 81857895 and 81857904.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7501 + ... + 14831.

It is an arithmetic number, because the mean of its divisors is an integer number (10239138).

Almost surely, 2^81857946 is an apocalyptic number.

81857946 is an abundant number, since it is smaller than the sum of its proper divisors (81968262).

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

81857946 is a wasteful number, since it uses less digits than its factorization.

81857946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9197.

The product of its digits is 483840, while the sum is 48.

The square root of 81857946 is about 9047.5381181844. The cubic root of 81857946 is about 434.1971291893.

The spelling of 81857946 in words is "eighty-one million, eight hundred fifty-seven thousand, nine hundred forty-six".