81427082506 has 64 divisors (see below), whose sum is σ = 155673964800. Its totient is φ = 31666246080.

The previous prime is 81427082489. The next prime is 81427082509. The reversal of 81427082506 is 60528072418.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81427082509) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4193436 + ... + 4212808.

It is an arithmetic number, because the mean of its divisors is an integer number (2432405700).

Almost surely, 2^81427082506 is an apocalyptic number.

81427082506 is a deficient number, since it is larger than the sum of its proper divisors (74246882294).

81427082506 is a wasteful number, since it uses less digits than its factorization.

81427082506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19964 (or 19950 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 43.

The spelling of 81427082506 in words is "eighty-one billion, four hundred twenty-seven million, eighty-two thousand, five hundred six".