81656065830 has 64 divisors (see below), whose sum is σ = 210904233408. Its totient is φ = 20158095360.

The previous prime is 81656065823. The next prime is 81656065831. The reversal of 81656065830 is 3856065618.

It is a super-3 number, since 3×81656065830³ (a number of 34 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81656065830.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81656065831) 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, 1281267 + ... + 1343486.

It is an arithmetic number, because the mean of its divisors is an integer number (3295378647).

Almost surely, 2^81656065830 is an apocalyptic number.

81656065830 is an abundant number, since it is smaller than the sum of its proper divisors (129248167578).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81656065830 is a wasteful number, since it uses less digits than its factorization.

81656065830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2624841.

The product of its (nonzero) digits is 1036800, while the sum is 48.

The spelling of 81656065830 in words is "eighty-one billion, six hundred fifty-six million, sixty-five thousand, eight hundred thirty".