20919235958191 has 8 divisors (see below), whose sum is σ = 20963716375680. Its totient is φ = 20874772648152.

The previous prime is 20919235958189. The next prime is 20919235958249. The reversal of 20919235958191 is 19185953291902.

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 20919235958191 - 2¹ = 20919235958189 is a prime.

It is a super-2 number, since 2×20919235958191² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20919235958171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1827145 + ... + 6721378.

It is an arithmetic number, because the mean of its divisors is an integer number (2620464546960).

Almost surely, 2^{20919235958191} is an apocalyptic number.

20919235958191 is a deficient number, since it is larger than the sum of its proper divisors (44480417489).

20919235958191 is an equidigital number, since it uses as much as digits as its factorization.

20919235958191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8553725.

The product of its (nonzero) digits is 15746400, while the sum is 64.

The spelling of 20919235958191 in words is "twenty trillion, nine hundred nineteen billion, two hundred thirty-five million, nine hundred fifty-eight thousand, one hundred ninety-one".