81945295 has 4 divisors (see below), whose sum is σ = 98334360. Its totient is φ = 65556232.

The previous prime is 81945293. The next prime is 81945301. The reversal of 81945295 is 59254918.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 59254918 = 2 ⋅29627459.

It is a cyclic number.

It is not a de Polignac number, because 81945295 - 2¹ = 81945293 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81945293) 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, 8194525 + ... + 8194534.

It is an arithmetic number, because the mean of its divisors is an integer number (24583590).

Almost surely, 2^81945295 is an apocalyptic number.

81945295 is a deficient number, since it is larger than the sum of its proper divisors (16389065).

81945295 is a wasteful number, since it uses less digits than its factorization.

81945295 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16389064.

The product of its digits is 129600, while the sum is 43.

The square root of 81945295 is about 9052.3640558696. The cubic root of 81945295 is about 434.3515153530.

The spelling of 81945295 in words is "eighty-one million, nine hundred forty-five thousand, two hundred ninety-five".