1221628107 has 16 divisors (see below), whose sum is σ = 1865104640. Its totient is φ = 696732192.

The previous prime is 1221628091. The next prime is 1221628117. The reversal of 1221628107 is 7018261221.

It is not a de Polignac number, because 1221628107 - 2⁴ = 1221628091 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221628117) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44632 + ... + 66597.

It is an arithmetic number, because the mean of its divisors is an integer number (116569040).

Almost surely, 2^1221628107 is an apocalyptic number.

1221628107 is a deficient number, since it is larger than the sum of its proper divisors (643476533).

1221628107 is a wasteful number, since it uses less digits than its factorization.

1221628107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111762.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 1221628107 is about 34951.7969065969. The cubic root of 1221628107 is about 1069.0048414687.

Adding to 1221628107 its reverse (7018261221), we get a palindrome (8239889328).

The spelling of 1221628107 in words is "one billion, two hundred twenty-one million, six hundred twenty-eight thousand, one hundred seven".