221001012 has 36 divisors (see below), whose sum is σ = 559890240. Its totient is φ = 73502352.

The previous prime is 221000981. The next prime is 221001031. The reversal of 221001012 is 210100122.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 221000985 and 221001003.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 10039 + ... + 23297.

Almost surely, 2^221001012 is an apocalyptic number.

It is an amenable number.

221001012 is an abundant number, since it is smaller than the sum of its proper divisors (338889228).

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

221001012 is a wasteful number, since it uses less digits than its factorization.

221001012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13732 (or 13727 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 221001012 is about 14866.1027845229. The cubic root of 221001012 is about 604.5952824498.

Adding to 221001012 its reverse (210100122), we get a palindrome (431101134).

The spelling of 221001012 in words is "two hundred twenty-one million, one thousand, twelve".