1221161 has 8 divisors (see below), whose sum is σ = 1338120. Its totient is φ = 1109248.

The previous prime is 1221131. The next prime is 1221163. The reversal of 1221161 is 1611221.

It can be written as a sum of positive squares in 4 ways, for example, as 337561 + 883600 = 581^2 + 940^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221161 - 2⁶ = 1221097 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 746 + ... + 1731.

It is an arithmetic number, because the mean of its divisors is an integer number (167265).

2^1221161 is an apocalyptic number.

It is an amenable number.

1221161 is a deficient number, since it is larger than the sum of its proper divisors (116959).

1221161 is a wasteful number, since it uses less digits than its factorization.

1221161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2523.

The product of its digits is 24, while the sum is 14.

The square root of 1221161 is about 1105.0615367481. The cubic root of 1221161 is about 106.8868574330.

Adding to 1221161 its reverse (1611221), we get a palindrome (2832382).

The spelling of 1221161 in words is "one million, two hundred twenty-one thousand, one hundred sixty-one".