1211136551 has 16 divisors (see below), whose sum is σ = 1329100800. Its totient is φ = 1099332000.

The previous prime is 1211136547. The next prime is 1211136571. The reversal of 1211136551 is 1556311121.

It is a cyclic number.

It is not a de Polignac number, because 1211136551 - 2² = 1211136547 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1211136551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211136571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49310 + ... + 69668.

It is an arithmetic number, because the mean of its divisors is an integer number (83068800).

Almost surely, 2^1211136551 is an apocalyptic number.

1211136551 is a deficient number, since it is larger than the sum of its proper divisors (117964249).

1211136551 is a wasteful number, since it uses less digits than its factorization.

1211136551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20510.

The product of its digits is 900, while the sum is 26.

The square root of 1211136551 is about 34801.3871993632. The cubic root of 1211136551 is about 1065.9357718320.

Adding to 1211136551 its reverse (1556311121), we get a palindrome (2767447672).

The spelling of 1211136551 in words is "one billion, two hundred eleven million, one hundred thirty-six thousand, five hundred fifty-one".