1211351242155 has 16 divisors (see below), whose sum is σ = 1957351712544. Its totient is φ = 639657420800.

The previous prime is 1211351242141. The next prime is 1211351242163. The reversal of 1211351242155 is 5512421531121.

It is not a de Polignac number, because 1211351242155 - 2¹⁰ = 1211351241131 is a prime.

It is a super-2 number, since 2×1211351242155² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 399784374 + ... + 399787403.

It is an arithmetic number, because the mean of its divisors is an integer number (122334482034).

Almost surely, 2^{1211351242155} is an apocalyptic number.

1211351242155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1211351242155 is a deficient number, since it is larger than the sum of its proper divisors (746000470389).

1211351242155 is a wasteful number, since it uses less digits than its factorization.

1211351242155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799571886.

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

Adding to 1211351242155 its reverse (5512421531121), we get a palindrome (6723772773276).

The spelling of 1211351242155 in words is "one trillion, two hundred eleven billion, three hundred fifty-one million, two hundred forty-two thousand, one hundred fifty-five".