16221746 has 4 divisors (see below), whose sum is σ = 24332622. Its totient is φ = 8110872.

The previous prime is 16221743. The next prime is 16221749. The reversal of 16221746 is 64712261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 64712261 = 1453 ⋅44537.

It is an interprime number because it is at equal distance from previous prime (16221743) and next prime (16221749).

It can be written as a sum of positive squares in only one way, i.e., 9066121 + 7155625 = 3011^2 + 2675^2 .

It is not an unprimeable number, because it can be changed into a prime (16221743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4055435 + ... + 4055438.

Almost surely, 2^16221746 is an apocalyptic number.

16221746 is a deficient number, since it is larger than the sum of its proper divisors (8110876).

16221746 is an equidigital number, since it uses as much as digits as its factorization.

16221746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8110875.

The product of its digits is 4032, while the sum is 29.

The square root of 16221746 is about 4027.6228721170. The cubic root of 16221746 is about 253.1429667885.

The spelling of 16221746 in words is "sixteen million, two hundred twenty-one thousand, seven hundred forty-six".