81517347 has 20 divisors (see below), whose sum is σ = 125975520. Its totient is φ = 52469424.

The previous prime is 81517343. The next prime is 81517357. The reversal of 81517347 is 74371518.

It is not a de Polignac number, because 81517347 - 2² = 81517343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81517343) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15003 + ... + 19700.

It is an arithmetic number, because the mean of its divisors is an integer number (6298776).

Almost surely, 2^81517347 is an apocalyptic number.

81517347 is a gapful number since it is divisible by the number (87) formed by its first and last digit.

81517347 is a deficient number, since it is larger than the sum of its proper divisors (44458173).

81517347 is a wasteful number, since it uses less digits than its factorization.

81517347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34744 (or 34735 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 81517347 is about 9028.6957529867. The cubic root of 81517347 is about 433.5940816623.

The spelling of 81517347 in words is "eighty-one million, five hundred seventeen thousand, three hundred forty-seven".