1211898240 has 512 divisors, whose sum is σ = 5040921600. Its totient is φ = 269402112.

The previous prime is 1211898217. The next prime is 1211898241. The reversal of 1211898240 is 428981121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1211898195 and 1211898204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211898241) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5201164 + ... + 5201396.

It is an arithmetic number, because the mean of its divisors is an integer number (9845550).

Almost surely, 2^1211898240 is an apocalyptic number.

1211898240 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 1211898240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2520460800).

1211898240 is an abundant number, since it is smaller than the sum of its proper divisors (3829023360).

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

1211898240 is a wasteful number, since it uses less digits than its factorization.

1211898240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311 (or 293 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 1211898240 is about 34812.3288505667. The cubic root of 1211898240 is about 1066.1591822052.

The spelling of 1211898240 in words is "one billion, two hundred eleven million, eight hundred ninety-eight thousand, two hundred forty".