219609421 has 2 divisors, whose sum is σ = 219609422. Its totient is φ = 219609420.

The previous prime is 219609413. The next prime is 219609437. The reversal of 219609421 is 124906912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199233225 + 20376196 = 14115^2 + 4514^2 .

It is a cyclic number.

It is not a de Polignac number, because 219609421 - 2³ = 219609413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (219609491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109804710 + 109804711.

It is an arithmetic number, because the mean of its divisors is an integer number (109804711).

Almost surely, 2^219609421 is an apocalyptic number.

It is an amenable number.

219609421 is a deficient number, since it is larger than the sum of its proper divisors (1).

219609421 is an equidigital number, since it uses as much as digits as its factorization.

219609421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 219609421 is about 14819.2247098153. The cubic root of 219609421 is about 603.3236118278.

The spelling of 219609421 in words is "two hundred nineteen million, six hundred nine thousand, four hundred twenty-one".