81074181 has 4 divisors (see below), whose sum is σ = 108098912. Its totient is φ = 54049452.

The previous prime is 81074177. The next prime is 81074183. The reversal of 81074181 is 18147018.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 81074181 - 2² = 81074177 is a prime.

It is a super-2 number, since 2×81074181² = 13146045649641522, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81074183) 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, 13512361 + ... + 13512366.

It is an arithmetic number, because the mean of its divisors is an integer number (27024728).

Almost surely, 2^81074181 is an apocalyptic number.

It is an amenable number.

81074181 is a deficient number, since it is larger than the sum of its proper divisors (27024731).

81074181 is a wasteful number, since it uses less digits than its factorization.

81074181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27024730.

The product of its (nonzero) digits is 1792, while the sum is 30.

The square root of 81074181 is about 9004.1202235421. The cubic root of 81074181 is about 432.8069141437.

The spelling of 81074181 in words is "eighty-one million, seventy-four thousand, one hundred eighty-one".