1215840 has 96 divisors (see below), whose sum is σ = 4082400. Its totient is φ = 303104.

The previous prime is 1215839. The next prime is 1215847. The reversal of 1215840 is 485121.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8086 + ... + 8234.

It is an arithmetic number, because the mean of its divisors is an integer number (42525).

2^1215840 is an apocalyptic number.

1215840 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 1215840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2041200).

1215840 is an abundant number, since it is smaller than the sum of its proper divisors (2866560).

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

1215840 is a wasteful number, since it uses less digits than its factorization.

1215840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184 (or 176 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 1215840 is about 1102.6513501556. The cubic root of 1215840 is about 106.7313843371.

The spelling of 1215840 in words is "one million, two hundred fifteen thousand, eight hundred forty".