1221136306 has 16 divisors (see below), whose sum is σ = 1974196224. Its totient is φ = 563146704.

The previous prime is 1221136297. The next prime is 1221136307. The reversal of 1221136306 is 6036311221.

It is not an unprimeable number, because it can be changed into a prime (1221136307) 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, 15055 + ... + 51661.

It is an arithmetic number, because the mean of its divisors is an integer number (123387264).

Almost surely, 2^1221136306 is an apocalyptic number.

1221136306 is a deficient number, since it is larger than the sum of its proper divisors (753059918).

1221136306 is a wasteful number, since it uses less digits than its factorization.

1221136306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37905.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 1221136306 is about 34944.7607804088. The cubic root of 1221136306 is about 1068.8613694871.

Adding to 1221136306 its reverse (6036311221), we get a palindrome (7257447527).

The spelling of 1221136306 in words is "one billion, two hundred twenty-one million, one hundred thirty-six thousand, three hundred six".