20164221 has 80 divisors (see below), whose sum is σ = 38890368. Its totient is φ = 10108800.

The previous prime is 20164219. The next prime is 20164231. The reversal of 20164221 is 12246102.

20164221 is a `hidden beast` number, since 2 + 0 + 1 + 642 + 21 = 666.

It is not a de Polignac number, because 20164221 - 2¹ = 20164219 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20164194 and 20164203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20164231) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 330531 + ... + 330591.

Almost surely, 2^20164221 is an apocalyptic number.

20164221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20164221 is a deficient number, since it is larger than the sum of its proper divisors (18726147).

20164221 is a wasteful number, since it uses less digits than its factorization.

20164221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 135 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 20164221 is about 4490.4588852366. The cubic root of 20164221 is about 272.1826780698.

The spelling of 20164221 in words is "twenty million, one hundred sixty-four thousand, two hundred twenty-one".