1215745440 has 288 divisors, whose sum is σ = 4741462656. Its totient is φ = 256389120.

The previous prime is 1215745423. The next prime is 1215745441. The reversal of 1215745440 is 445475121.

It is not an unprimeable number, because it can be changed into a prime (1215745441) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 566770 + ... + 568910.

It is an arithmetic number, because the mean of its divisors is an integer number (16463412).

Almost surely, 2^1215745440 is an apocalyptic number.

1215745440 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 1215745440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2370731328).

1215745440 is an abundant number, since it is smaller than the sum of its proper divisors (3525717216).

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

1215745440 is a wasteful number, since it uses less digits than its factorization.

1215745440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2192 (or 2171 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 33.

The square root of 1215745440 is about 34867.5413529546. The cubic root of 1215745440 is about 1067.2861731150.

The spelling of 1215745440 in words is "one billion, two hundred fifteen million, seven hundred forty-five thousand, four hundred forty".