1211436155 has 4 divisors (see below), whose sum is σ = 1453723392. Its totient is φ = 969148920.

The previous prime is 1211436113. The next prime is 1211436157. The reversal of 1211436155 is 5516341121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5516341121 = 11369 ⋅485209.

It is not a de Polignac number, because 1211436155 - 2²² = 1207241851 is a prime.

It is a super-3 number, since 3×1211436155³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211436157) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121143611 + ... + 121143620.

It is an arithmetic number, because the mean of its divisors is an integer number (363430848).

Almost surely, 2^1211436155 is an apocalyptic number.

1211436155 is a deficient number, since it is larger than the sum of its proper divisors (242287237).

1211436155 is an equidigital number, since it uses as much as digits as its factorization.

1211436155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242287236.

The product of its digits is 3600, while the sum is 29.

The square root of 1211436155 is about 34805.6914167784. The cubic root of 1211436155 is about 1066.0236596072.

Adding to 1211436155 its reverse (5516341121), we get a palindrome (6727777276).

The spelling of 1211436155 in words is "one billion, two hundred eleven million, four hundred thirty-six thousand, one hundred fifty-five".