81703440 has 480 divisors, whose sum is σ = 357477120. Its totient is φ = 16257024.

The previous prime is 81703417. The next prime is 81703441. The reversal of 81703440 is 4430718.

It is not an unprimeable number, because it can be changed into a prime (81703441) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1900059 + ... + 1900101.

It is an arithmetic number, because the mean of its divisors is an integer number (744744).

Almost surely, 2^81703440 is an apocalyptic number.

81703440 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 81703440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (178738560).

81703440 is an abundant number, since it is smaller than the sum of its proper divisors (275773680).

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

81703440 is a wasteful number, since it uses less digits than its factorization.

81703440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 81703440 is about 9038.9955194148. The cubic root of 81703440 is about 433.9237763168.

The spelling of 81703440 in words is "eighty-one million, seven hundred three thousand, four hundred forty".