81347216 has 20 divisors (see below), whose sum is σ = 157875312. Its totient is φ = 40605216.

The previous prime is 81347213. The next prime is 81347249. The reversal of 81347216 is 61274318.

It is not an unprimeable number, because it can be changed into a prime (81347213) 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, 6335 + ... + 14241.

Almost surely, 2^81347216 is an apocalyptic number.

It is an amenable number.

81347216 is a deficient number, since it is larger than the sum of its proper divisors (76528096).

81347216 is a wasteful number, since it uses less digits than its factorization.

81347216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8558 (or 8552 counting only the distinct ones).

The product of its digits is 8064, while the sum is 32.

The square root of 81347216 is about 9019.2691499921. The cubic root of 81347216 is about 433.2922270015.

The spelling of 81347216 in words is "eighty-one million, three hundred forty-seven thousand, two hundred sixteen".