81606300672 has 352 divisors, whose sum is σ = 250246241280. Its totient is φ = 23451402240.

The previous prime is 81606300637. The next prime is 81606300697. The reversal of 81606300672 is 27600360618.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 81606300672.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35901328 + ... + 35903600.

Almost surely, 2^81606300672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81606300672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125123120640).

81606300672 is an abundant number, since it is smaller than the sum of its proper divisors (168639940608).

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

81606300672 is a wasteful number, since it uses less digits than its factorization.

81606300672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2369 (or 2351 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

The spelling of 81606300672 in words is "eighty-one billion, six hundred six million, three hundred thousand, six hundred seventy-two".