81001835 has 4 divisors (see below), whose sum is σ = 97202208. Its totient is φ = 64801464.

The previous prime is 81001831. The next prime is 81001871. The reversal of 81001835 is 53810018.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81001835 - 2² = 81001831 is a prime.

It is a super-2 number, since 2×81001835² = 13122594546734450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81001831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8100179 + ... + 8100188.

It is an arithmetic number, because the mean of its divisors is an integer number (24300552).

Almost surely, 2^81001835 is an apocalyptic number.

81001835 is a deficient number, since it is larger than the sum of its proper divisors (16200373).

81001835 is a wasteful number, since it uses less digits than its factorization.

81001835 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16200372.

The product of its (nonzero) digits is 960, while the sum is 26.

The square root of 81001835 is about 9000.1019438671. The cubic root of 81001835 is about 432.6781383860.

The spelling of 81001835 in words is "eighty-one million, one thousand, eight hundred thirty-five".