1216653123 has 16 divisors (see below), whose sum is σ = 1854594560. Its totient is φ = 694987776.

The previous prime is 1216653083. The next prime is 1216653133. The reversal of 1216653123 is 3213566121.

It is not a de Polignac number, because 1216653123 - 2²¹ = 1214555971 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1216653133) 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, 64218 + ... + 80976.

It is an arithmetic number, because the mean of its divisors is an integer number (115912160).

Almost surely, 2^1216653123 is an apocalyptic number.

1216653123 is a deficient number, since it is larger than the sum of its proper divisors (637941437).

1216653123 is a wasteful number, since it uses less digits than its factorization.

1216653123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20226.

The product of its digits is 6480, while the sum is 30.

The square root of 1216653123 is about 34880.5550844593. Note that the first 3 decimals coincide. The cubic root of 1216653123 is about 1067.5517211730.

The spelling of 1216653123 in words is "one billion, two hundred sixteen million, six hundred fifty-three thousand, one hundred twenty-three".