1561224240 has 480 divisors, whose sum is σ = 5947744320. Its totient is φ = 376012800.

The previous prime is 1561224229. The next prime is 1561224253. The reversal of 1561224240 is 424221651.

1561224240 is a `hidden beast` number, since 1 + 5 + 612 + 2 + 4 + 2 + 40 = 666.

It is a super-2 number, since 2×1561224240² = 4874842255127155200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 25593810 + ... + 25593870.

It is an arithmetic number, because the mean of its divisors is an integer number (12391134).

Almost surely, 2^1561224240 is an apocalyptic number.

1561224240 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 1561224240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2973872160).

1561224240 is an abundant number, since it is smaller than the sum of its proper divisors (4386520080).

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

1561224240 is a wasteful number, since it uses less digits than its factorization.

1561224240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 1561224240 is about 39512.3302274113. The cubic root of 1561224240 is about 1160.0813062312.

Adding to 1561224240 its reverse (424221651), we get a palindrome (1985445891).

The spelling of 1561224240 in words is "one billion, five hundred sixty-one million, two hundred twenty-four thousand, two hundred forty".