81753408 has 336 divisors, whose sum is σ = 291876480. Its totient is φ = 22302720.

The previous prime is 81753403. The next prime is 81753437. The reversal of 81753408 is 80435718.

It is a super-2 number, since 2×81753408² = 13367239439228928, which contains 22 as substring.

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 (81753403) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3554485 + ... + 3554507.

It is an arithmetic number, because the mean of its divisors is an integer number (868680).

Almost surely, 2^81753408 is an apocalyptic number.

81753408 is a gapful number since it is divisible by the number (88) 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 81753408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145938240).

81753408 is an abundant number, since it is smaller than the sum of its proper divisors (210123072).

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

81753408 is a wasteful number, since it uses less digits than its factorization.

81753408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83 (or 56 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 81753408 is about 9041.7591208791. The cubic root of 81753408 is about 434.0122176546.

The spelling of 81753408 in words is "eighty-one million, seven hundred fifty-three thousand, four hundred eight".