20193001891 has 2 divisors, whose sum is σ = 20193001892. Its totient is φ = 20193001890.

The previous prime is 20193001889. The next prime is 20193001903. The reversal of 20193001891 is 19810039102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20193001891 - 2¹ = 20193001889 is a prime.

It is a super-3 number, since 3×20193001891³ (a number of 32 digits) contains 333 as substring.

Together with 20193001889, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20193001831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10096500945 + 10096500946.

It is an arithmetic number, because the mean of its divisors is an integer number (10096500946).

Almost surely, 2^20193001891 is an apocalyptic number.

20193001891 is a deficient number, since it is larger than the sum of its proper divisors (1).

20193001891 is an equidigital number, since it uses as much as digits as its factorization.

20193001891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 34.

The spelling of 20193001891 in words is "twenty billion, one hundred ninety-three million, one thousand, eight hundred ninety-one".