81539827004 has 24 divisors (see below), whose sum is σ = 151307242128. Its totient is φ = 38316130560.

The previous prime is 81539827001. The next prime is 81539827007. The reversal of 81539827004 is 40072893518.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81539827001) and next prime (81539827007).

It is a self number, because there is not a number n which added to its sum of digits gives 81539827004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81539827001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 820679 + ... + 914654.

It is an arithmetic number, because the mean of its divisors is an integer number (6304468422).

Almost surely, 2^81539827004 is an apocalyptic number.

It is an amenable number.

81539827004 is a deficient number, since it is larger than the sum of its proper divisors (69767415124).

81539827004 is a wasteful number, since it uses less digits than its factorization.

81539827004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1736045 (or 1736043 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 47.

The spelling of 81539827004 in words is "eighty-one billion, five hundred thirty-nine million, eight hundred twenty-seven thousand, four".