1211210440 has 64 divisors (see below), whose sum is σ = 2981914560. Its totient is φ = 439115520.

The previous prime is 1211210387. The next prime is 1211210443. The reversal of 1211210440 is 440121121.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1211210443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148714 + ... + 156646.

It is an arithmetic number, because the mean of its divisors is an integer number (46592415).

Almost surely, 2^1211210440 is an apocalyptic number.

1211210440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211210440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1490957280).

1211210440 is an abundant number, since it is smaller than the sum of its proper divisors (1770704120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211210440 is a wasteful number, since it uses less digits than its factorization.

1211210440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8302 (or 8298 counting only the distinct ones).

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

The square root of 1211210440 is about 34802.4487644189. The cubic root of 1211210440 is about 1065.9574482555.

Adding to 1211210440 its reverse (440121121), we get a palindrome (1651331561).

The spelling of 1211210440 in words is "one billion, two hundred eleven million, two hundred ten thousand, four hundred forty".