1561422240 has 216 divisors, whose sum is σ = 6198568740. Its totient is φ = 356880384.

The previous prime is 1561422211. The next prime is 1561422251. The reversal of 1561422240 is 422241651.

1561422240 is a `hidden beast` number, since 1 + 5 + 614 + 2 + 2 + 2 + 40 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1486565136 + 74857104 = 38556^2 + 8652^2 .

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 35 ways as a sum of consecutive naturals, for example, 59496 + ... + 81624.

Almost surely, 2^1561422240 is an apocalyptic number.

1561422240 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 1561422240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3099284370).

1561422240 is an abundant number, since it is smaller than the sum of its proper divisors (4637146500).

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

1561422240 is a wasteful number, since it uses less digits than its factorization.

1561422240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22164 (or 22146 counting only the distinct ones).

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

The square root of 1561422240 is about 39514.8356949640. The cubic root of 1561422240 is about 1160.1303460346.

Adding to 1561422240 its reverse (422241651), we get a palindrome (1983663891).

It can be divided in two parts, 1561 and 422240, that added together give a square (423801 = 651²).

The spelling of 1561422240 in words is "one billion, five hundred sixty-one million, four hundred twenty-two thousand, two hundred forty".