1215795840 has 192 divisors, whose sum is σ = 4508408160. Its totient is φ = 277874688.

The previous prime is 1215795809. The next prime is 1215795853. The reversal of 1215795840 is 485975121.

It is a tau number, because it is divible by the number of its divisors (192).

It is a super-2 number, since 2×1215795840² = 2956319049122611200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 1215795792 and 1215795801.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 87619 + ... + 100541.

Almost surely, 2^1215795840 is an apocalyptic number.

1215795840 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 1215795840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2254204080).

1215795840 is an abundant number, since it is smaller than the sum of its proper divisors (3292612320).

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

1215795840 is a wasteful number, since it uses less digits than its factorization.

1215795840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12959 (or 12940 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 42.

The square root of 1215795840 is about 34868.2640806794. The cubic root of 1215795840 is about 1067.3009213997.

The spelling of 1215795840 in words is "one billion, two hundred fifteen million, seven hundred ninety-five thousand, eight hundred forty".