1209555858420 has 576 divisors, whose sum is σ = 4557443304960. Its totient is φ = 252854784000.

The previous prime is 1209555858419. The next prime is 1209555858439. The reversal of 1209555858420 is 248585559021.

1209555858420 is a `hidden beast` number, since 1 + 2 + 0 + 9 + 5 + 5 + 58 + 584 + 2 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 929711770 + ... + 929713070.

It is an arithmetic number, because the mean of its divisors is an integer number (7912227960).

Almost surely, 2^{1209555858420} is an apocalyptic number.

1209555858420 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 1209555858420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2278721652480).

1209555858420 is an abundant number, since it is smaller than the sum of its proper divisors (3347887446540).

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

1209555858420 is a wasteful number, since it uses less digits than its factorization.

1209555858420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1816 (or 1811 counting only the distinct ones).

The product of its (nonzero) digits is 5760000, while the sum is 54.

The spelling of 1209555858420 in words is "one trillion, two hundred nine billion, five hundred fifty-five million, eight hundred fifty-eight thousand, four hundred twenty".