221212011 has 16 divisors (see below), whose sum is σ = 303377408. Its totient is φ = 143272800.

The previous prime is 221212009. The next prime is 221212021. The reversal of 221212011 is 110212122.

It is not a de Polignac number, because 221212011 - 2¹ = 221212009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221212021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108996 + ... + 111006.

It is an arithmetic number, because the mean of its divisors is an integer number (18961088).

Almost surely, 2^221212011 is an apocalyptic number.

221212011 is a deficient number, since it is larger than the sum of its proper divisors (82165397).

221212011 is a wasteful number, since it uses less digits than its factorization.

221212011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3042.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 221212011 is about 14873.1977395582. The cubic root of 221212011 is about 604.7876321316.

Adding to 221212011 its reverse (110212122), we get a palindrome (331424133).

The spelling of 221212011 in words is "two hundred twenty-one million, two hundred twelve thousand, eleven".