11561344273920 has 640 divisors, whose sum is σ = 43540512086016. Its totient is φ = 2561767243776.

The previous prime is 11561344273909. The next prime is 11561344273931. The reversal of 11561344273920 is 2937244316511.

It is an interprime number because it is at equal distance from previous prime (11561344273909) and next prime (11561344273931).

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 11561344273920.

It is a congruent number.

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, 550975749 + ... + 550996731.

Almost surely, 2^{11561344273920} is an apocalyptic number.

11561344273920 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 11561344273920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21770256043008).

11561344273920 is an abundant number, since it is smaller than the sum of its proper divisors (31979167812096).

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

11561344273920 is a wasteful number, since it uses less digits than its factorization.

11561344273920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21330 (or 21314 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 48.

The spelling of 11561344273920 in words is "eleven trillion, five hundred sixty-one billion, three hundred forty-four million, two hundred seventy-three thousand, nine hundred twenty".