81901248 has 224 divisors, whose sum is σ = 269687040. Its totient is φ = 21565440.

The previous prime is 81901247. The next prime is 81901273. The reversal of 81901248 is 84210918.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (81901241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 521586 + ... + 521742.

It is an arithmetic number, because the mean of its divisors is an integer number (1203960).

Almost surely, 2^81901248 is an apocalyptic number.

81901248 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 81901248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134843520).

81901248 is an abundant number, since it is smaller than the sum of its proper divisors (187785792).

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

81901248 is a wasteful number, since it uses less digits than its factorization.

81901248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 33.

The square root of 81901248 is about 9049.9308284649. The cubic root of 81901248 is about 434.2736776113.

The spelling of 81901248 in words is "eighty-one million, nine hundred one thousand, two hundred forty-eight".