1215518464 has 72 divisors (see below), whose sum is σ = 2566242000. Its totient is φ = 573014016.

The previous prime is 1215518449. The next prime is 1215518471. The reversal of 1215518464 is 4648155121.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1307952 + ... + 1308880.

It is an arithmetic number, because the mean of its divisors is an integer number (35642250).

Almost surely, 2^1215518464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1215518464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1283121000).

1215518464 is an abundant number, since it is smaller than the sum of its proper divisors (1350723536).

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

1215518464 is an equidigital number, since it uses as much as digits as its factorization.

1215518464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1233 (or 1219 counting only the distinct ones).

The product of its digits is 38400, while the sum is 37.

The square root of 1215518464 is about 34864.2863687183. The cubic root of 1215518464 is about 1067.2197492799.

The spelling of 1215518464 in words is "one billion, two hundred fifteen million, five hundred eighteen thousand, four hundred sixty-four".