1221432166 has 4 divisors (see below), whose sum is σ = 1832148252. Its totient is φ = 610716082.

The previous prime is 1221432139. The next prime is 1221432169. The reversal of 1221432166 is 6612341221.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×1221432166² = 2983793072278903112, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221432169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305358040 + ... + 305358043.

It is an arithmetic number, because the mean of its divisors is an integer number (458037063).

Almost surely, 2^1221432166 is an apocalyptic number.

1221432166 is a deficient number, since it is larger than the sum of its proper divisors (610716086).

1221432166 is an equidigital number, since it uses as much as digits as its factorization.

1221432166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610716085.

The product of its digits is 3456, while the sum is 28.

The square root of 1221432166 is about 34948.9937766454. The cubic root of 1221432166 is about 1068.9476846640.

Adding to 1221432166 its reverse (6612341221), we get a palindrome (7833773387).

The spelling of 1221432166 in words is "one billion, two hundred twenty-one million, four hundred thirty-two thousand, one hundred sixty-six".