81358368 has 192 divisors, whose sum is σ = 268692480. Its totient is φ = 20984832.

The previous prime is 81358357. The next prime is 81358397. The reversal of 81358368 is 86385318.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 585243 + ... + 585381.

It is an arithmetic number, because the mean of its divisors is an integer number (1399440).

Almost surely, 2^81358368 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81358368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134346240).

81358368 is an abundant number, since it is smaller than the sum of its proper divisors (187334112).

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

81358368 is a wasteful number, since it uses less digits than its factorization.

81358368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239 (or 231 counting only the distinct ones).

The product of its digits is 138240, while the sum is 42.

The square root of 81358368 is about 9019.8873607158. The cubic root of 81358368 is about 433.3120263028.

The spelling of 81358368 in words is "eighty-one million, three hundred fifty-eight thousand, three hundred sixty-eight".