1561222080 has 224 divisors, whose sum is σ = 6008705280. Its totient is φ = 378455040.

The previous prime is 1561222043. The next prime is 1561222087. The reversal of 1561222080 is 802221651.

It is a happy number.

1561222080 is a `hidden beast` number, since 1 + 561 + 2 + 2 + 20 + 80 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561222087) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 86827 + ... + 103253.

Almost surely, 2^1561222080 is an apocalyptic number.

1561222080 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 1561222080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3004352640).

1561222080 is an abundant number, since it is smaller than the sum of its proper divisors (4447483200).

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

1561222080 is a wasteful number, since it uses less digits than its factorization.

1561222080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16464 (or 16448 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 1561222080 is about 39512.3028941620. The cubic root of 1561222080 is about 1160.0807712287.

The spelling of 1561222080 in words is "one billion, five hundred sixty-one million, two hundred twenty-two thousand, eighty".