221664012 has 48 divisors (see below), whose sum is σ = 539492352. Its totient is φ = 70755840.

The previous prime is 221663971. The next prime is 221664019. The reversal of 221664012 is 210466122.

It is a super-2 number, since 2×221664012² = 98269868431872288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221664019) 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 in 15 ways as a sum of consecutive naturals, for example, 33013 + ... + 39155.

It is an arithmetic number, because the mean of its divisors is an integer number (11239424).

Almost surely, 2^221664012 is an apocalyptic number.

It is an amenable number.

221664012 is an abundant number, since it is smaller than the sum of its proper divisors (317828340).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221664012 is a wasteful number, since it uses less digits than its factorization.

221664012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6278 (or 6276 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 221664012 is about 14888.3851374150. The cubic root of 221664012 is about 605.1992713796.

The spelling of 221664012 in words is "two hundred twenty-one million, six hundred sixty-four thousand, twelve".