81748240 has 160 divisors (see below), whose sum is σ = 238270464. Its totient is φ = 25436160.

The previous prime is 81748237. The next prime is 81748273. The reversal of 81748240 is 4284718.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 81748196 and 81748205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 294982 + ... + 295258.

Almost surely, 2^81748240 is an apocalyptic number.

81748240 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 81748240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119135232).

81748240 is an abundant number, since it is smaller than the sum of its proper divisors (156522224).

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

81748240 is a wasteful number, since it uses less digits than its factorization.

81748240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345 (or 339 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 34.

The square root of 81748240 is about 9041.4733312663. The cubic root of 81748240 is about 434.0030721749.

The spelling of 81748240 in words is "eighty-one million, seven hundred forty-eight thousand, two hundred forty".