191011001920 has 28 divisors (see below), whose sum is σ = 454844949084. Its totient is φ = 76404400640.

The previous prime is 191011001911. The next prime is 191011001927. The reversal of 191011001920 is 29100110191.

It can be written as a sum of positive squares in 2 ways, for example, as 90466202176 + 100544799744 = 300776^2 + 317088^2 .

It is not an unprimeable number, because it can be changed into a prime (191011001927) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 298454371 + ... + 298455010.

Almost surely, 2^191011001920 is an apocalyptic number.

191011001920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191011001920 is an abundant number, since it is smaller than the sum of its proper divisors (263833947164).

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

191011001920 is an equidigital number, since it uses as much as digits as its factorization.

191011001920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596909398 (or 596909388 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 25.

The spelling of 191011001920 in words is "one hundred ninety-one billion, eleven million, one thousand, nine hundred twenty".