1205621113 has 16 divisors (see below), whose sum is σ = 1311269904. Its totient is φ = 1103984640.

The previous prime is 1205621101. The next prime is 1205621119. The reversal of 1205621113 is 3111265021.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 126630009 + 1078991104 = 11253^2 + 32848^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1205621113 is a prime.

It is a super-2 number, since 2×1205621113² = 2907044536222717538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1205621119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 274531 + ... + 278887.

It is an arithmetic number, because the mean of its divisors is an integer number (81954369).

Almost surely, 2^1205621113 is an apocalyptic number.

It is an amenable number.

1205621113 is a deficient number, since it is larger than the sum of its proper divisors (105648791).

1205621113 is a wasteful number, since it uses less digits than its factorization.

1205621113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4812.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 1205621113 is about 34722.0551379091. The cubic root of 1205621113 is about 1064.3152417451.

Adding to 1205621113 its reverse (3111265021), we get a palindrome (4316886134).

The spelling of 1205621113 in words is "one billion, two hundred five million, six hundred twenty-one thousand, one hundred thirteen".