191020806144 has 416 divisors, whose sum is σ = 649387722240. Its totient is φ = 54356410368.

The previous prime is 191020806131. The next prime is 191020806157. The reversal of 191020806144 is 441608020191.

191020806144 is a `hidden beast` number, since 1 + 9 + 10 + 20 + 8 + 0 + 614 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (191020806131) and next prime (191020806157).

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

It is a junction number, because it is equal to n+sod(n) for n = 191020806099 and 191020806108.

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, 342945514 + ... + 342946070.

Almost surely, 2^191020806144 is an apocalyptic number.

191020806144 is a gapful number since it is divisible by the number (14) 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 191020806144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324693861120).

191020806144 is an abundant number, since it is smaller than the sum of its proper divisors (458366916096).

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

191020806144 is an equidigital number, since it uses as much as digits as its factorization.

191020806144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1040 (or 1012 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The spelling of 191020806144 in words is "one hundred ninety-one billion, twenty million, eight hundred six thousand, one hundred forty-four".