1561365227520 has 1440 divisors, whose sum is σ = 6676018188840. Its totient is φ = 347807416320.

The previous prime is 1561365227519. The next prime is 1561365227549. The reversal of 1561365227520 is 257225631651.

It is a happy number.

1561365227520 is a `hidden beast` number, since 1 + 5 + 6 + 1 + 36 + 522 + 75 + 20 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 424019764224 + 1137345463296 = 651168^2 + 1066464^2 .

It is a tau number, because it is divible by the number of its divisors (1440).

It is a super-2 number, since 2×1561365227520² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 1666344492 + ... + 1666345428.

Almost surely, 2^{1561365227520} is an apocalyptic number.

1561365227520 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 1561365227520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3338009094420).

1561365227520 is an abundant number, since it is smaller than the sum of its proper divisors (5114652961320).

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

1561365227520 is an equidigital number, since it uses as much as digits as its factorization.

1561365227520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1031 (or 995 counting only the distinct ones).

The product of its (nonzero) digits is 756000, while the sum is 45.

The spelling of 1561365227520 in words is "one trillion, five hundred sixty-one billion, three hundred sixty-five million, two hundred twenty-seven thousand, five hundred twenty".