81887946 has 32 divisors (see below), whose sum is σ = 198184320. Its totient is φ = 22020096.

The previous prime is 81887941. The next prime is 81887977. The reversal of 81887946 is 64978818.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (81887941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56631 + ... + 58058.

It is an arithmetic number, because the mean of its divisors is an integer number (6193260).

Almost surely, 2^81887946 is an apocalyptic number.

81887946 is an abundant number, since it is smaller than the sum of its proper divisors (116296374).

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

81887946 is a wasteful number, since it uses less digits than its factorization.

81887946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114718.

The product of its digits is 774144, while the sum is 51.

The square root of 81887946 is about 9049.1958758776. The cubic root of 81887946 is about 434.2501654696.

The spelling of 81887946 in words is "eighty-one million, eight hundred eighty-seven thousand, nine hundred forty-six".