1212153855 has 64 divisors (see below), whose sum is σ = 2185560576. Its totient is φ = 568512000.

The previous prime is 1212153827. The next prime is 1212153857. The reversal of 1212153855 is 5583512121.

It is a Cunningham number, because it is equal to 34816²-1.

It is not a de Polignac number, because 1212153855 - 2⁶ = 1212153791 is a prime.

It is a super-2 number, since 2×1212153855² = 2938633936382722050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212153857) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1287685 + ... + 1288625.

It is an arithmetic number, because the mean of its divisors is an integer number (34149384).

Almost surely, 2^1212153855 is an apocalyptic number.

1212153855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1212153855 is a deficient number, since it is larger than the sum of its proper divisors (973406721).

1212153855 is a wasteful number, since it uses less digits than its factorization.

1212153855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1208.

The product of its digits is 12000, while the sum is 33.

The square root of 1212153855 is about 34815.9999856388. Note that the first 4 decimals coincide. The cubic root of 1212153855 is about 1066.2341354513.

Adding to 1212153855 its reverse (5583512121), we get a palindrome (6795665976).

The spelling of 1212153855 in words is "one billion, two hundred twelve million, one hundred fifty-three thousand, eight hundred fifty-five".