19969421 has 2 divisors, whose sum is σ = 19969422. Its totient is φ = 19969420.

The previous prime is 19969357. The next prime is 19969423. The reversal of 19969421 is 12496991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13912900 + 6056521 = 3730^2 + 2461^2 .

It is a cyclic number.

It is not a de Polignac number, because 19969421 - 2⁶ = 19969357 is a prime.

Together with 19969423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19969423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9984710 + 9984711.

It is an arithmetic number, because the mean of its divisors is an integer number (9984711).

Almost surely, 2^19969421 is an apocalyptic number.

It is an amenable number.

19969421 is a deficient number, since it is larger than the sum of its proper divisors (1).

19969421 is an equidigital number, since it uses as much as digits as its factorization.

19969421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 41.

The square root of 19969421 is about 4468.7158110580. The cubic root of 19969421 is about 271.3033508006.

The spelling of 19969421 in words is "nineteen million, nine hundred sixty-nine thousand, four hundred twenty-one".