2221161605 has 32 divisors (see below), whose sum is σ = 3044871648. Its totient is φ = 1540915200.

The previous prime is 2221161587. The next prime is 2221161629. The reversal of 2221161605 is 5061611222.

It can be written as a sum of positive squares in 16 ways, for example, as 2563201 + 2218598404 = 1601^2 + 47102^2 .

It is not a de Polignac number, because 2221161605 - 2¹⁰ = 2221160581 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 728885 + ... + 731925.

It is an arithmetic number, because the mean of its divisors is an integer number (95152239).

Almost surely, 2^2221161605 is an apocalyptic number.

It is an amenable number.

2221161605 is a deficient number, since it is larger than the sum of its proper divisors (823710043).

2221161605 is a wasteful number, since it uses less digits than its factorization.

2221161605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3737.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 2221161605 is about 47129.2011920423. The cubic root of 2221161605 is about 1304.7482385497.

Adding to 2221161605 its reverse (5061611222), we get a palindrome (7282772827).

The spelling of 2221161605 in words is "two billion, two hundred twenty-one million, one hundred sixty-one thousand, six hundred five".