1561843388020 has 48 divisors (see below), whose sum is σ = 3545806642560. Its totient is φ = 575860316544.

The previous prime is 1561843388009. The next prime is 1561843388047. The reversal of 1561843388020 is 208833481651.

It is a happy number.

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 15 ways as a sum of consecutive naturals, for example, 55528024 + ... + 55556143.

It is an arithmetic number, because the mean of its divisors is an integer number (73870971720).

Almost surely, 2^{1561843388020} is an apocalyptic number.

1561843388020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1561843388020 is an abundant number, since it is smaller than the sum of its proper divisors (1983963254540).

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

1561843388020 is a wasteful number, since it uses less digits than its factorization.

1561843388020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111084232 (or 111084230 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 49.

The spelling of 1561843388020 in words is "one trillion, five hundred sixty-one billion, eight hundred forty-three million, three hundred eighty-eight thousand, twenty".