1211123451 has 4 divisors (see below), whose sum is σ = 1614831272. Its totient is φ = 807415632.

The previous prime is 1211123413. The next prime is 1211123453. The reversal of 1211123451 is 1543211121.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1211123451 - 2⁷ = 1211123323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211123453) 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, 201853906 + ... + 201853911.

It is an arithmetic number, because the mean of its divisors is an integer number (403707818).

Almost surely, 2^1211123451 is an apocalyptic number.

1211123451 is a deficient number, since it is larger than the sum of its proper divisors (403707821).

1211123451 is an equidigital number, since it uses as much as digits as its factorization.

1211123451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403707820.

The product of its digits is 240, while the sum is 21.

The square root of 1211123451 is about 34801.1989879659. The cubic root of 1211123451 is about 1065.9319286625.

Adding to 1211123451 its reverse (1543211121), we get a palindrome (2754334572).

The spelling of 1211123451 in words is "one billion, two hundred eleven million, one hundred twenty-three thousand, four hundred fifty-one".