19434721 has 2 divisors, whose sum is σ = 19434722. Its totient is φ = 19434720.

The previous prime is 19434719. The next prime is 19434733. The reversal of 19434721 is 12743491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14167696 + 5267025 = 3764^2 + 2295^2 .

It is a cyclic number.

It is not a de Polignac number, because 19434721 - 2¹ = 19434719 is a prime.

Together with 19434719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (19434781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9717360 + 9717361.

It is an arithmetic number, because the mean of its divisors is an integer number (9717361).

Almost surely, 2^19434721 is an apocalyptic number.

It is an amenable number.

19434721 is a deficient number, since it is larger than the sum of its proper divisors (1).

19434721 is an equidigital number, since it uses as much as digits as its factorization.

19434721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 19434721 is about 4408.4828456057. The cubic root of 19434721 is about 268.8599437673.

The spelling of 19434721 in words is "nineteen million, four hundred thirty-four thousand, seven hundred twenty-one".