16461221 has 4 divisors (see below), whose sum is σ = 18812832. Its totient is φ = 14109612.

The previous prime is 16461199. The next prime is 16461251. The reversal of 16461221 is 12216461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12216461 = 1093 ⋅11177.

It is a cyclic number.

It is not a de Polignac number, because 16461221 - 2⁶ = 16461157 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 (16461251) 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, 1175795 + ... + 1175808.

It is an arithmetic number, because the mean of its divisors is an integer number (4703208).

Almost surely, 2^16461221 is an apocalyptic number.

It is an amenable number.

16461221 is a deficient number, since it is larger than the sum of its proper divisors (2351611).

16461221 is an equidigital number, since it uses as much as digits as its factorization.

16461221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2351610.

The product of its digits is 576, while the sum is 23.

The square root of 16461221 is about 4057.2430294475. The cubic root of 16461221 is about 254.3825687610.

Adding to 16461221 its reverse (12216461), we get a palindrome (28677682).

The spelling of 16461221 in words is "sixteen million, four hundred sixty-one thousand, two hundred twenty-one".