221013 has 12 divisors (see below), whose sum is σ = 343980. Its totient is φ = 135936.

The previous prime is 220973. The next prime is 221021. The reversal of 221013 is 310122.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 66564 + 154449 = 258^2 + 393^2 .

It is not a de Polignac number, because 221013 - 2⁸ = 220757 is a prime.

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

It is a Curzon number.

221013 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 220986 and 221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221083) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 828 + ... + 1061.

It is an arithmetic number, because the mean of its divisors is an integer number (28665).

2²²¹⁰¹³ is an apocalyptic number.

It is an amenable number.

221013 is a deficient number, since it is larger than the sum of its proper divisors (122967).

221013 is a wasteful number, since it uses less digits than its factorization.

221013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1908 (or 1905 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 221013 is about 470.1201973964. The cubic root of 221013 is about 60.4606214160.

Adding to 221013 its reverse (310122), we get a palindrome (531135).

It can be divided in two parts, 22 and 1013, that added together give a triangular number (1035 = T₄₅).

The spelling of 221013 in words is "two hundred twenty-one thousand, thirteen".