1561223056 has 10 divisors (see below), whose sum is σ = 3024869702. Its totient is φ = 780611520.

The previous prime is 1561223009. The next prime is 1561223057. The reversal of 1561223056 is 6503221651.

It can be written as a sum of positive squares in only one way, i.e., 925376400 + 635846656 = 30420^2 + 25216^2 .

It is not an unprimeable number, because it can be changed into a prime (1561223057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48788205 + ... + 48788236.

Almost surely, 2^1561223056 is an apocalyptic number.

1561223056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1561223056 is a deficient number, since it is larger than the sum of its proper divisors (1463646646).

1561223056 is an equidigital number, since it uses as much as digits as its factorization.

1561223056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97576449 (or 97576443 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 1561223056 is about 39512.3152447436. The cubic root of 1561223056 is about 1160.0810129706.

The spelling of 1561223056 in words is "one billion, five hundred sixty-one million, two hundred twenty-three thousand, fifty-six".