81618347 has 2 divisors, whose sum is σ = 81618348. Its totient is φ = 81618346.

The previous prime is 81618323. The next prime is 81618353. The reversal of 81618347 is 74381618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81618347 - 2¹² = 81614251 is a prime.

It is a Chen prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81618347.

It is not a weakly prime, because it can be changed into another prime (81612347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40809173 + 40809174.

It is an arithmetic number, because the mean of its divisors is an integer number (40809174).

Almost surely, 2^81618347 is an apocalyptic number.

81618347 is a deficient number, since it is larger than the sum of its proper divisors (1).

81618347 is an equidigital number, since it uses as much as digits as its factorization.

81618347 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 38.

The square root of 81618347 is about 9034.2872989517. The cubic root of 81618347 is about 433.7730821237.

The spelling of 81618347 in words is "eighty-one million, six hundred eighteen thousand, three hundred forty-seven".