1215656420 has 48 divisors (see below), whose sum is σ = 2806284096. Its totient is φ = 438672000.

The previous prime is 1215656401. The next prime is 1215656441. The reversal of 1215656420 is 246565121.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7730 + ... + 49910.

It is an arithmetic number, because the mean of its divisors is an integer number (58464252).

Almost surely, 2^1215656420 is an apocalyptic number.

1215656420 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 1215656420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1403142048).

1215656420 is an abundant number, since it is smaller than the sum of its proper divisors (1590627676).

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

1215656420 is a wasteful number, since it uses less digits than its factorization.

1215656420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42332 (or 42330 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 1215656420 is about 34866.2647841721. The cubic root of 1215656420 is about 1067.2601226686.

The spelling of 1215656420 in words is "one billion, two hundred fifteen million, six hundred fifty-six thousand, four hundred twenty".