1211545040 has 20 divisors (see below), whose sum is σ = 2816842404. Its totient is φ = 484617984.

The previous prime is 1211545037. The next prime is 1211545043. The reversal of 1211545040 is 405451121.

1211545040 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1211545037) and next prime (1211545043).

It can be written as a sum of positive squares in 2 ways, for example, as 187032976 + 1024512064 = 13676^2 + 32008^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 1211544997 and 1211545015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211545043) 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, 7572077 + ... + 7572236.

Almost surely, 2^1211545040 is an apocalyptic number.

1211545040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211545040 is an abundant number, since it is smaller than the sum of its proper divisors (1605297364).

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

1211545040 is a wasteful number, since it uses less digits than its factorization.

1211545040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15144326 (or 15144320 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 1211545040 is about 34807.2555654708. The cubic root of 1211545040 is about 1066.0555970473.

Adding to 1211545040 its reverse (405451121), we get a palindrome (1616996161).

The spelling of 1211545040 in words is "one billion, two hundred eleven million, five hundred forty-five thousand, forty".