1215144440 has 16 divisors (see below), whose sum is σ = 2734075080. Its totient is φ = 486057760.

The previous prime is 1215144419. The next prime is 1215144443. The reversal of 1215144440 is 444415121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215144443) 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, 15189266 + ... + 15189345.

Almost surely, 2^1215144440 is an apocalyptic number.

1215144440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1215144440 is an abundant number, since it is smaller than the sum of its proper divisors (1518930640).

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

1215144440 is a wasteful number, since it uses less digits than its factorization.

1215144440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30378622 (or 30378618 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 26.

The square root of 1215144440 is about 34858.9219569395. The cubic root of 1215144440 is about 1067.1102742533.

Adding to 1215144440 its reverse (444415121), we get a palindrome (1659559561).

The spelling of 1215144440 in words is "one billion, two hundred fifteen million, one hundred forty-four thousand, four hundred forty".