81907200 has 300 divisors, whose sum is σ = 306981840. Its totient is φ = 21565440.

The previous prime is 81907187. The next prime is 81907211. The reversal of 81907200 is 270918.

It is a tau number, because it is divible by the number of its divisors (300).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 1036761 + ... + 1036839.

Almost surely, 2^81907200 is an apocalyptic number.

81907200 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 81907200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153490920).

81907200 is an abundant number, since it is smaller than the sum of its proper divisors (225074640).

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

81907200 is an equidigital number, since it uses as much as digits as its factorization.

81907200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 81907200 is about 9050.2596647831. The cubic root of 81907200 is about 434.2841973301.

The spelling of 81907200 in words is "eighty-one million, nine hundred seven thousand, two hundred".