81446840 has 16 divisors (see below), whose sum is σ = 183255480. Its totient is φ = 32578720.

The previous prime is 81446839. The next prime is 81446861. The reversal of 81446840 is 4864418.

It is a self number, because there is not a number n which added to its sum of digits gives 81446840.

It is a congruent 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, 1018046 + ... + 1018125.

Almost surely, 2^81446840 is an apocalyptic number.

It is an amenable number.

81446840 is an abundant number, since it is smaller than the sum of its proper divisors (101808640).

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

81446840 is a wasteful number, since it uses less digits than its factorization.

81446840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2036182 (or 2036178 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 35.

The square root of 81446840 is about 9024.7903022730. The cubic root of 81446840 is about 433.4690357371.

The spelling of 81446840 in words is "eighty-one million, four hundred forty-six thousand, eight hundred forty".