1211440551 has 24 divisors (see below), whose sum is σ = 1709434224. Its totient is φ = 763015680.

The previous prime is 1211440493. The next prime is 1211440583. The reversal of 1211440551 is 1550441121.

It is not a de Polignac number, because 1211440551 - 2⁶ = 1211440487 is a prime.

It is a super-3 number, since 3×1211440551³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211440151) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 454615 + ... + 457271.

It is an arithmetic number, because the mean of its divisors is an integer number (71226426).

Almost surely, 2^1211440551 is an apocalyptic number.

1211440551 is a deficient number, since it is larger than the sum of its proper divisors (497993673).

1211440551 is a wasteful number, since it uses less digits than its factorization.

1211440551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3119 (or 3100 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 1211440551 is about 34805.7545673126. The cubic root of 1211440551 is about 1066.0249490504.

Adding to 1211440551 its reverse (1550441121), we get a palindrome (2761881672).

The spelling of 1211440551 in words is "one billion, two hundred eleven million, four hundred forty thousand, five hundred fifty-one".