19999471 has 2 divisors, whose sum is σ = 19999472. Its totient is φ = 19999470.

The previous prime is 19999439. The next prime is 19999481. The reversal of 19999471 is 17499991.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (17499991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19999471 - 2⁵ = 19999439 is a prime.

It is a super-3 number, since 3×19999471³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19999411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9999735 + 9999736.

It is an arithmetic number, because the mean of its divisors is an integer number (9999736).

Almost surely, 2^19999471 is an apocalyptic number.

19999471 is a deficient number, since it is larger than the sum of its proper divisors (1).

19999471 is an equidigital number, since it uses as much as digits as its factorization.

19999471 is an evil number, because the sum of its binary digits is even.

The product of its digits is 183708, while the sum is 49.

The square root of 19999471 is about 4472.0768106105. The cubic root of 19999471 is about 271.4393684269.

The spelling of 19999471 in words is "nineteen million, nine hundred ninety-nine thousand, four hundred seventy-one".