191011281408 has 240 divisors, whose sum is σ = 579547864896. Its totient is φ = 62795243520.

The previous prime is 191011281379. The next prime is 191011281431. The reversal of 191011281408 is 804182110191.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9071853 + ... + 9092883.

Almost surely, 2^191011281408 is an apocalyptic number.

191011281408 is a gapful number since it is divisible by the number (18) 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 191011281408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (289773932448).

191011281408 is an abundant number, since it is smaller than the sum of its proper divisors (388536583488).

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

191011281408 is an frugal number, since it uses more digits than its factorization.

191011281408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21137 (or 21109 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 36.

Adding to 191011281408 its reverse (804182110191), we get a palindrome (995193391599).

The spelling of 191011281408 in words is "one hundred ninety-one billion, eleven million, two hundred eighty-one thousand, four hundred eight".