16221965 has 16 divisors (see below), whose sum is σ = 20072448. Its totient is φ = 12578496.

The previous prime is 16221929. The next prime is 16221971. The reversal of 16221965 is 56912261.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 16221965 - 2⁶ = 16221901 is a prime.

It is a super-2 number, since 2×16221965² = 526304296922450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42164 + ... + 42546.

It is an arithmetic number, because the mean of its divisors is an integer number (1254528).

Almost surely, 2^16221965 is an apocalyptic number.

It is an amenable number.

16221965 is a deficient number, since it is larger than the sum of its proper divisors (3850483).

16221965 is a wasteful number, since it uses less digits than its factorization.

16221965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 628.

The product of its digits is 6480, while the sum is 32.

The square root of 16221965 is about 4027.6500592777. The cubic root of 16221965 is about 253.1441059602.

The spelling of 16221965 in words is "sixteen million, two hundred twenty-one thousand, nine hundred sixty-five".