1215430656 has 144 divisors (see below), whose sum is σ = 3548367648. Its totient is φ = 367001600.

The previous prime is 1215430651. The next prime is 1215430681. The reversal of 1215430656 is 6560345121.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215430651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4325236 + ... + 4325516.

It is an arithmetic number, because the mean of its divisors is an integer number (24641442).

Almost surely, 2^1215430656 is an apocalyptic number.

1215430656 is a gapful number since it is divisible by the number (16) 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 1215430656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1774183824).

1215430656 is an abundant number, since it is smaller than the sum of its proper divisors (2332936992).

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

1215430656 is an frugal number, since it uses more digits than its factorization.

1215430656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 1215430656 is about 34863.0270630650. The cubic root of 1215430656 is about 1067.1940503180.

Adding to 1215430656 its reverse (6560345121), we get a palindrome (7775775777).

The spelling of 1215430656 in words is "one billion, two hundred fifteen million, four hundred thirty thousand, six hundred fifty-six".