1243854135220 has 48 divisors (see below), whose sum is σ = 2637995488128. Its totient is φ = 492609962880.

The previous prime is 1243854135193. The next prime is 1243854135221. The reversal of 1243854135220 is 225314583421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243854135221) 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, 10399155 + ... + 10518085.

It is an arithmetic number, because the mean of its divisors is an integer number (54958239336).

Almost surely, 2^{1243854135220} is an apocalyptic number.

1243854135220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1243854135220 is an abundant number, since it is smaller than the sum of its proper divisors (1394141352908).

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

1243854135220 is a wasteful number, since it uses less digits than its factorization.

1243854135220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124120 (or 124118 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 40.

The spelling of 1243854135220 in words is "one trillion, two hundred forty-three billion, eight hundred fifty-four million, one hundred thirty-five thousand, two hundred twenty".