1215140305 has 4 divisors (see below), whose sum is σ = 1458168372. Its totient is φ = 972112240.

The previous prime is 1215140249. The next prime is 1215140309. The reversal of 1215140305 is 5030415121.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 637411009 + 577729296 = 25247^2 + 24036^2 .

It is not a de Polignac number, because 1215140305 - 2²³ = 1206751697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1215140309) 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, 121514026 + ... + 121514035.

It is an arithmetic number, because the mean of its divisors is an integer number (364542093).

Almost surely, 2^1215140305 is an apocalyptic number.

It is an amenable number.

1215140305 is a deficient number, since it is larger than the sum of its proper divisors (243028067).

1215140305 is an equidigital number, since it uses as much as digits as its factorization.

1215140305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243028066.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 1215140305 is about 34858.8626463917. The cubic root of 1215140305 is about 1067.1090638332.

Adding to 1215140305 its reverse (5030415121), we get a palindrome (6245555426).

The spelling of 1215140305 in words is "one billion, two hundred fifteen million, one hundred forty thousand, three hundred five".