1211040421 has 4 divisors (see below), whose sum is σ = 1215542700. Its totient is φ = 1206538144.

The previous prime is 1211040409. The next prime is 1211040443. The reversal of 1211040421 is 1240401121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1240401121 = 347 ⋅3574643.

It can be written as a sum of positive squares in 2 ways, for example, as 362483521 + 848556900 = 19039^2 + 29130^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211040421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211040395 and 1211040404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211040401) 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, 2250736 + ... + 2251273.

It is an arithmetic number, because the mean of its divisors is an integer number (303885675).

Almost surely, 2^1211040421 is an apocalyptic number.

It is an amenable number.

1211040421 is a deficient number, since it is larger than the sum of its proper divisors (4502279).

1211040421 is an equidigital number, since it uses as much as digits as its factorization.

1211040421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4502278.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 1211040421 is about 34800.0060488500. The cubic root of 1211040421 is about 1065.9075693647.

Adding to 1211040421 its reverse (1240401121), we get a palindrome (2451441542).

The spelling of 1211040421 in words is "one billion, two hundred eleven million, forty thousand, four hundred twenty-one".