1611221101 has 4 divisors (see below), whose sum is σ = 1841395552. Its totient is φ = 1381046652.

The previous prime is 1611221099. The next prime is 1611221111. The reversal of 1611221101 is 1011221161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1611221101 - 2¹ = 1611221099 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1611221111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115087215 + ... + 115087228.

It is an arithmetic number, because the mean of its divisors is an integer number (460348888).

Almost surely, 2^1611221101 is an apocalyptic number.

It is an amenable number.

1611221101 is a deficient number, since it is larger than the sum of its proper divisors (230174451).

1611221101 is an equidigital number, since it uses as much as digits as its factorization.

1611221101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230174450.

The product of its (nonzero) digits is 24, while the sum is 16.

The square root of 1611221101 is about 40140.0186970559. The cubic root of 1611221101 is about 1172.3349530595.

Adding to 1611221101 its reverse (1011221161), we get a palindrome (2622442262).

The spelling of 1611221101 in words is "one billion, six hundred eleven million, two hundred twenty-one thousand, one hundred one".