1215260640 has 288 divisors, whose sum is σ = 4791267936. Its totient is φ = 277217280.

The previous prime is 1215260561. The next prime is 1215260659. The reversal of 1215260640 is 460625121.

1215260640 is a `hidden beast` number, since 1 + 2 + 1 + 52 + 606 + 4 + 0 = 666.

1215260640 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 267024 + ... + 271536.

It is an arithmetic number, because the mean of its divisors is an integer number (16636347).

Almost surely, 2^1215260640 is an apocalyptic number.

1215260640 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 1215260640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2395633968).

1215260640 is an abundant number, since it is smaller than the sum of its proper divisors (3576007296).

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

1215260640 is a wasteful number, since it uses less digits than its factorization.

1215260640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4562 (or 4551 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 1215260640 is about 34860.5886353056. The cubic root of 1215260640 is about 1067.1442878398.

Adding to 1215260640 its reverse (460625121), we get a palindrome (1675885761).

The spelling of 1215260640 in words is "one billion, two hundred fifteen million, two hundred sixty thousand, six hundred forty".