81146071 has 4 divisors (see below), whose sum is σ = 81164200. Its totient is φ = 81127944.

The previous prime is 81145991. The next prime is 81146081. The reversal of 81146071 is 17064118.

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 81146071 - 2⁷ = 81145943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81146081) 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, 3025 + ... + 13093.

It is an arithmetic number, because the mean of its divisors is an integer number (20291050).

Almost surely, 2^81146071 is an apocalyptic number.

81146071 is a deficient number, since it is larger than the sum of its proper divisors (18129).

81146071 is a wasteful number, since it uses less digits than its factorization.

81146071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18128.

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 81146071 is about 9008.1114002881. Note that the first 3 decimals coincide. The cubic root of 81146071 is about 432.9348023592.

The spelling of 81146071 in words is "eighty-one million, one hundred forty-six thousand, seventy-one".