81001135 has 8 divisors (see below), whose sum is σ = 97706160. Its totient is φ = 64464384.

The previous prime is 81001097. The next prime is 81001139. The reversal of 81001135 is 53110018.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81001135 - 2⁷ = 81001007 is a prime.

It is a super-2 number, since 2×81001135² = 13122367742576450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81001139) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41005 + ... + 42934.

It is an arithmetic number, because the mean of its divisors is an integer number (12213270).

Almost surely, 2^81001135 is an apocalyptic number.

81001135 is a deficient number, since it is larger than the sum of its proper divisors (16705025).

81001135 is a wasteful number, since it uses less digits than its factorization.

81001135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84137.

The product of its (nonzero) digits is 120, while the sum is 19.

The square root of 81001135 is about 9000.0630553347. The cubic root of 81001135 is about 432.6768920127.

The spelling of 81001135 in words is "eighty-one million, one thousand, one hundred thirty-five".