81955200 has 96 divisors (see below), whose sum is σ = 269971560. Its totient is φ = 21852160.

The previous prime is 81955199. The next prime is 81955213. The reversal of 81955200 is 255918.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5332 + ... + 13868.

Almost surely, 2^81955200 is an apocalyptic number.

81955200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81955200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134985780).

81955200 is an abundant number, since it is smaller than the sum of its proper divisors (188016360).

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

81955200 is a wasteful number, since it uses less digits than its factorization.

81955200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8564 (or 8547 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 81955200 is about 9052.9111339944. The cubic root of 81955200 is about 434.3690151514.

The spelling of 81955200 in words is "eighty-one million, nine hundred fifty-five thousand, two hundred".