213444121 has 6 divisors (see below), whose sum is σ = 234612266. Its totient is φ = 194040000.

The previous prime is 213444097. The next prime is 213444137. The reversal of 213444121 is 121444312.

It is a happy number.

213444121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 212110096 + 1334025 = 14564^2 + 1155^2 .

It is not a de Polignac number, because 213444121 - 2⁹ = 213443609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213444092 and 213444101.

It is not an unprimeable number, because it can be changed into a prime (213444191) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 881880 + ... + 882121.

Almost surely, 2^213444121 is an apocalyptic number.

It is an amenable number.

213444121 is a deficient number, since it is larger than the sum of its proper divisors (21168145).

213444121 is a wasteful number, since it uses less digits than its factorization.

213444121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1764023 (or 1764012 counting only the distinct ones).

The product of its digits is 768, while the sum is 22.

The square root of 213444121 is about 14609.7269310552. The cubic root of 213444121 is about 597.6240492192.

Adding to 213444121 its reverse (121444312), we get a palindrome (334888433).

It can be divided in two parts, 213444 and 121, that multiplied together give a square (25826724 = 5082²).

The spelling of 213444121 in words is "two hundred thirteen million, four hundred forty-four thousand, one hundred twenty-one".