1215355140 has 144 divisors (see below), whose sum is σ = 3963697920. Its totient is φ = 300464640.

The previous prime is 1215355117. The next prime is 1215355189. The reversal of 1215355140 is 415535121.

1215355140 is a `hidden beast` number, since 1 + 21 + 53 + 551 + 40 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 156960 + ... + 164520.

It is an arithmetic number, because the mean of its divisors is an integer number (27525680).

Almost surely, 2^1215355140 is an apocalyptic number.

1215355140 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 1215355140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1981848960).

1215355140 is an abundant number, since it is smaller than the sum of its proper divisors (2748342780).

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

1215355140 is a wasteful number, since it uses less digits than its factorization.

1215355140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7642 (or 7637 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The square root of 1215355140 is about 34861.9440077572. The cubic root of 1215355140 is about 1067.1719478929.

The spelling of 1215355140 in words is "one billion, two hundred fifteen million, three hundred fifty-five thousand, one hundred forty".