81446904 has 256 divisors, whose sum is σ = 290304000. Its totient is φ = 20545920.

The previous prime is 81446899. The next prime is 81446909. The reversal of 81446904 is 40964418.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81446899) and next prime (81446909).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81446909) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 981247 + ... + 981329.

It is an arithmetic number, because the mean of its divisors is an integer number (1134000).

Almost surely, 2^81446904 is an apocalyptic number.

81446904 is a gapful number since it is divisible by the number (84) 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 81446904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145152000).

81446904 is an abundant number, since it is smaller than the sum of its proper divisors (208857096).

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

81446904 is a wasteful number, since it uses less digits than its factorization.

81446904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 81446904 is about 9024.7938480610. The cubic root of 81446904 is about 433.4691492754.

It can be divided in two parts, 81 and 446904, that added together give a triangular number (446985 = T₉₄₅).

The spelling of 81446904 in words is "eighty-one million, four hundred forty-six thousand, nine hundred four".