221638964 has 24 divisors (see below), whose sum is σ = 401119488. Its totient is φ = 107046720.

The previous prime is 221638961. The next prime is 221638973. The reversal of 221638964 is 469836122.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221638961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83384 + ... + 86000.

It is an arithmetic number, because the mean of its divisors is an integer number (16713312).

Almost surely, 2^221638964 is an apocalyptic number.

It is an amenable number.

221638964 is a deficient number, since it is larger than the sum of its proper divisors (179480524).

221638964 is a wasteful number, since it uses less digits than its factorization.

221638964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3335 (or 3333 counting only the distinct ones).

The product of its digits is 124416, while the sum is 41.

The square root of 221638964 is about 14887.5439210099. The cubic root of 221638964 is about 605.1764747120.

The spelling of 221638964 in words is "two hundred twenty-one million, six hundred thirty-eight thousand, nine hundred sixty-four".