191638087680 has 384 divisors, whose sum is σ = 683061724800. Its totient is φ = 45543063552.

The previous prime is 191638087661. The next prime is 191638087727. The reversal of 191638087680 is 86780836191.

It is a tau number, because it is divible by the number of its divisors (384).

It is a self number, because there is not a number n which added to its sum of digits gives 191638087680.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11573167 + ... + 11589713.

It is an arithmetic number, because the mean of its divisors is an integer number (1778806575).

Almost surely, 2^191638087680 is an apocalyptic number.

191638087680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191638087680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (341530862400).

191638087680 is an abundant number, since it is smaller than the sum of its proper divisors (491423637120).

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

191638087680 is a wasteful number, since it uses less digits than its factorization.

191638087680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16619 (or 16599 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 57.

The spelling of 191638087680 in words is "one hundred ninety-one billion, six hundred thirty-eight million, eighty-seven thousand, six hundred eighty".