1561744137540 has 96 divisors (see below), whose sum is σ = 4412282958720. Its totient is φ = 412713957376.

The previous prime is 1561744137533. The next prime is 1561744137559. The reversal of 1561744137540 is 457314471651.

It is a super-2 number, since 2×1561744137540² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1561744137540.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54693547 + ... + 54722093.

It is an arithmetic number, because the mean of its divisors is an integer number (45961280820).

Almost surely, 2^{1561744137540} is an apocalyptic number.

1561744137540 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 1561744137540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2206141479360).

1561744137540 is an abundant number, since it is smaller than the sum of its proper divisors (2850538821180).

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

1561744137540 is a wasteful number, since it uses less digits than its factorization.

1561744137540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36741 (or 36739 counting only the distinct ones).

The product of its (nonzero) digits is 1411200, while the sum is 48.

The spelling of 1561744137540 in words is "one trillion, five hundred sixty-one billion, seven hundred forty-four million, one hundred thirty-seven thousand, five hundred forty".