16704421 has 4 divisors (see below), whose sum is σ = 17687052. Its totient is φ = 15721792.

The previous prime is 16704419. The next prime is 16704449. The reversal of 16704421 is 12440761.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12440761 = 67 ⋅185683.

It can be written as a sum of positive squares in 2 ways, for example, as 13322500 + 3381921 = 3650^2 + 1839^2 .

It is a cyclic number.

It is not a de Polignac number, because 16704421 - 2¹ = 16704419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16704461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 491290 + ... + 491323.

It is an arithmetic number, because the mean of its divisors is an integer number (4421763).

Almost surely, 2^16704421 is an apocalyptic number.

It is an amenable number.

16704421 is a deficient number, since it is larger than the sum of its proper divisors (982631).

16704421 is an equidigital number, since it uses as much as digits as its factorization.

16704421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 982630.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 16704421 is about 4087.1042316046. The cubic root of 16704421 is about 255.6292086872.

The spelling of 16704421 in words is "sixteen million, seven hundred four thousand, four hundred twenty-one".