1220154555 has 16 divisors (see below), whose sum is σ = 2019566880. Its totient is φ = 628309248.

The previous prime is 1220154527. The next prime is 1220154557. The reversal of 1220154555 is 5554510221.

It is not a de Polignac number, because 1220154555 - 2⁷ = 1220154427 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1220154557) 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, 1402042 + ... + 1402911.

It is an arithmetic number, because the mean of its divisors is an integer number (126222930).

Almost surely, 2^1220154555 is an apocalyptic number.

1220154555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1220154555 is a deficient number, since it is larger than the sum of its proper divisors (799412325).

1220154555 is a wasteful number, since it uses less digits than its factorization.

1220154555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2804990.

The product of its (nonzero) digits is 10000, while the sum is 30.

The square root of 1220154555 is about 34930.7107714687. The cubic root of 1220154555 is about 1068.5748502688.

Adding to 1220154555 its reverse (5554510221), we get a palindrome (6774664776).

The spelling of 1220154555 in words is "one billion, two hundred twenty million, one hundred fifty-four thousand, five hundred fifty-five".