1215984420 has 192 divisors, whose sum is σ = 4551321600. Its totient is φ = 263295360.

The previous prime is 1215984409. The next prime is 1215984443. The reversal of 1215984420 is 244895121.

1215984420 is a `hidden beast` number, since 1 + 2 + 1 + 598 + 44 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 63355 + ... + 80285.

It is an arithmetic number, because the mean of its divisors is an integer number (23704800).

Almost surely, 2^1215984420 is an apocalyptic number.

1215984420 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 1215984420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2275660800).

1215984420 is an abundant number, since it is smaller than the sum of its proper divisors (3335337180).

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

1215984420 is a wasteful number, since it uses less digits than its factorization.

1215984420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16975 (or 16967 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 1215984420 is about 34870.9681540390. The cubic root of 1215984420 is about 1067.3561009498.

The spelling of 1215984420 in words is "one billion, two hundred fifteen million, nine hundred eighty-four thousand, four hundred twenty".