81944016 has 80 divisors (see below), whose sum is σ = 263935488. Its totient is φ = 21283200.

The previous prime is 81943993. The next prime is 81944039. The reversal of 81944016 is 61044918.

It is an interprime number because it is at equal distance from previous prime (81943993) and next prime (81944039).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7390 + ... + 14781.

Almost surely, 2^81944016 is an apocalyptic number.

It is an amenable number.

81944016 is an abundant number, since it is smaller than the sum of its proper divisors (181991472).

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

81944016 is a wasteful number, since it uses less digits than its factorization.

81944016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22200 (or 22194 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 81944016 is about 9052.2934110644. The cubic root of 81944016 is about 434.3492555589.

The spelling of 81944016 in words is "eighty-one million, nine hundred forty-four thousand, sixteen".