21011012191 has 8 divisors (see below), whose sum is σ = 22647408560. Its totient is φ = 19377496512.

The previous prime is 21011012177. The next prime is 21011012273. The reversal of 21011012191 is 19121011012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21011012191 - 2⁵ = 21011012159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011012161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 705006 + ... + 734203.

It is an arithmetic number, because the mean of its divisors is an integer number (2830926070).

Almost surely, 2^21011012191 is an apocalyptic number.

21011012191 is a deficient number, since it is larger than the sum of its proper divisors (1636396369).

21011012191 is a wasteful number, since it uses less digits than its factorization.

21011012191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1440345.

The product of its (nonzero) digits is 36, while the sum is 19.

The spelling of 21011012191 in words is "twenty-one billion, eleven million, twelve thousand, one hundred ninety-one".