19408421 has 2 divisors, whose sum is σ = 19408422. Its totient is φ = 19408420.

The previous prime is 19408399. The next prime is 19408427. The reversal of 19408421 is 12480491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17556100 + 1852321 = 4190^2 + 1361^2 .

It is a cyclic number.

It is not a de Polignac number, because 19408421 - 2¹⁰ = 19407397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19408427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9704210 + 9704211.

It is an arithmetic number, because the mean of its divisors is an integer number (9704211).

Almost surely, 2^19408421 is an apocalyptic number.

It is an amenable number.

19408421 is a deficient number, since it is larger than the sum of its proper divisors (1).

19408421 is an equidigital number, since it uses as much as digits as its factorization.

19408421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 19408421 is about 4405.4989501758. The cubic root of 19408421 is about 268.7386109470.

The spelling of 19408421 in words is "nineteen million, four hundred eight thousand, four hundred twenty-one".