16421408 has 12 divisors (see below), whose sum is σ = 32329710. Its totient is φ = 8210688.

The previous prime is 16421387. The next prime is 16421417. The reversal of 16421408 is 80412461.

It can be written as a sum of positive squares in only one way, i.e., 16418704 + 2704 = 4052^2 + 52^2 .

It is a nialpdrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 256553 + ... + 256616.

Almost surely, 2^16421408 is an apocalyptic number.

It is an amenable number.

16421408 is a deficient number, since it is larger than the sum of its proper divisors (15908302).

16421408 is an equidigital number, since it uses as much as digits as its factorization.

16421408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513179 (or 513171 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 16421408 is about 4052.3336486523. Note that the first 3 decimals coincide. The cubic root of 16421408 is about 254.1773205364.

Adding to 16421408 its reverse (80412461), we get a palindrome (96833869).

The spelling of 16421408 in words is "sixteen million, four hundred twenty-one thousand, four hundred eight".