1212023155 has 16 divisors (see below), whose sum is σ = 1700861184. Its totient is φ = 811772640.

The previous prime is 1212023123. The next prime is 1212023173. The reversal of 1212023155 is 5513202121.

It is not a de Polignac number, because 1212023155 - 2⁵ = 1212023123 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 401161 + ... + 404170.

It is an arithmetic number, because the mean of its divisors is an integer number (106303824).

Almost surely, 2^1212023155 is an apocalyptic number.

1212023155 is a deficient number, since it is larger than the sum of its proper divisors (488838029).

1212023155 is an equidigital number, since it uses as much as digits as its factorization.

1212023155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 805386.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 1212023155 is about 34814.1229244685. The cubic root of 1212023155 is about 1066.1958119855.

Adding to 1212023155 its reverse (5513202121), we get a palindrome (6725225276).

The spelling of 1212023155 in words is "one billion, two hundred twelve million, twenty-three thousand, one hundred fifty-five".