81242384247 has 24 divisors (see below), whose sum is σ = 120234245040. Its totient is φ = 52830933120.

The previous prime is 81242384207. The next prime is 81242384291. The reversal of 81242384247 is 74248324218.

81242384247 is a `hidden beast` number, since 8 + 1 + 24 + 2 + 384 + 247 = 666.

It is not a de Polignac number, because 81242384247 - 2²⁷ = 81108166519 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81242384207) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2399029 + ... + 2432657.

It is an arithmetic number, because the mean of its divisors is an integer number (5009760210).

Almost surely, 2^81242384247 is an apocalyptic number.

81242384247 is a deficient number, since it is larger than the sum of its proper divisors (38991860793).

81242384247 is a wasteful number, since it uses less digits than its factorization.

81242384247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40223 (or 40220 counting only the distinct ones).

The product of its digits is 688128, while the sum is 45.

The spelling of 81242384247 in words is "eighty-one billion, two hundred forty-two million, three hundred eighty-four thousand, two hundred forty-seven".