19901143 has 2 divisors, whose sum is σ = 19901144. Its totient is φ = 19901142.

The previous prime is 19901107. The next prime is 19901149. The reversal of 19901143 is 34110991.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (34110991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19901143 - 2⁹ = 19900631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19901149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9950571 + 9950572.

It is an arithmetic number, because the mean of its divisors is an integer number (9950572).

Almost surely, 2^19901143 is an apocalyptic number.

19901143 is a deficient number, since it is larger than the sum of its proper divisors (1).

19901143 is an equidigital number, since it uses as much as digits as its factorization.

19901143 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 19901143 is about 4461.0697147657. The cubic root of 19901143 is about 270.9937907920.

The spelling of 19901143 in words is "nineteen million, nine hundred one thousand, one hundred forty-three".