19814021 has 2 divisors, whose sum is σ = 19814022. Its totient is φ = 19814020.

The previous prime is 19813987. The next prime is 19814051. The reversal of 19814021 is 12041891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19483396 + 330625 = 4414^2 + 575^2 .

It is a cyclic number.

It is not a de Polignac number, because 19814021 - 2⁶ = 19813957 is a prime.

It is a super-3 number, since 3×19814021³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19814051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9907010 + 9907011.

It is an arithmetic number, because the mean of its divisors is an integer number (9907011).

Almost surely, 2^19814021 is an apocalyptic number.

It is an amenable number.

19814021 is a deficient number, since it is larger than the sum of its proper divisors (1).

19814021 is an equidigital number, since it uses as much as digits as its factorization.

19814021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 19814021 is about 4451.2943061541. The cubic root of 19814021 is about 270.5977656796.

The spelling of 19814021 in words is "nineteen million, eight hundred fourteen thousand, twenty-one".