19868501 has 2 divisors, whose sum is σ = 19868502. Its totient is φ = 19868500.

The previous prime is 19868473. The next prime is 19868503. The reversal of 19868501 is 10586891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17648401 + 2220100 = 4201^2 + 1490^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19868501 is a prime.

It is a Sophie Germain prime.

Together with 19868503, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19868503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9934250 + 9934251.

It is an arithmetic number, because the mean of its divisors is an integer number (9934251).

Almost surely, 2^19868501 is an apocalyptic number.

It is an amenable number.

19868501 is a deficient number, since it is larger than the sum of its proper divisors (1).

19868501 is an equidigital number, since it uses as much as digits as its factorization.

19868501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 38.

The square root of 19868501 is about 4457.4096737904. The cubic root of 19868501 is about 270.8455477147.

The spelling of 19868501 in words is "nineteen million, eight hundred sixty-eight thousand, five hundred one".