1216622553 has 16 divisors (see below), whose sum is σ = 1641315456. Its totient is φ = 801561600.

The previous prime is 1216622551. The next prime is 1216622581. The reversal of 1216622553 is 3552266121.

It is not a de Polignac number, because 1216622553 - 2¹ = 1216622551 is a prime.

It is a super-3 number, since 3×1216622553³ (a number of 28 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1216622551) 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, 82425 + ... + 96057.

It is an arithmetic number, because the mean of its divisors is an integer number (102582216).

Almost surely, 2^1216622553 is an apocalyptic number.

It is an amenable number.

1216622553 is a deficient number, since it is larger than the sum of its proper divisors (424692903).

1216622553 is a wasteful number, since it uses less digits than its factorization.

1216622553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13984.

The product of its digits is 21600, while the sum is 33.

The square root of 1216622553 is about 34880.1168719372. The cubic root of 1216622553 is about 1067.5427798873.

Adding to 1216622553 its reverse (3552266121), we get a palindrome (4768888674).

The spelling of 1216622553 in words is "one billion, two hundred sixteen million, six hundred twenty-two thousand, five hundred fifty-three".