1220236155 has 24 divisors (see below), whose sum is σ = 2164267248. Its totient is φ = 635656896.

The previous prime is 1220236151. The next prime is 1220236163. The reversal of 1220236155 is 5516320221.

It is a happy number.

1220236155 is a `hidden beast` number, since 1 + 2 + 20 + 23 + 615 + 5 = 666.

It is not a de Polignac number, because 1220236155 - 2² = 1220236151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1220236151) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 313372 + ... + 317241.

It is an arithmetic number, because the mean of its divisors is an integer number (90177802).

Almost surely, 2^1220236155 is an apocalyptic number.

1220236155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1220236155 is a deficient number, since it is larger than the sum of its proper divisors (944031093).

1220236155 is a wasteful number, since it uses less digits than its factorization.

1220236155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 630667 (or 630664 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 1220236155 is about 34931.8787785599. The cubic root of 1220236155 is about 1068.5986706840.

Adding to 1220236155 its reverse (5516320221), we get a palindrome (6736556376).

The spelling of 1220236155 in words is "one billion, two hundred twenty million, two hundred thirty-six thousand, one hundred fifty-five".