1561522266 has 128 divisors (see below), whose sum is σ = 3715891200. Its totient is φ = 485274240.

The previous prime is 1561522229. The next prime is 1561522343. The reversal of 1561522266 is 6622251651.

1561522266 is a `hidden beast` number, since 15 + 61 + 522 + 2 + 66 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 1561522266.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7002231 + ... + 7002453.

It is an arithmetic number, because the mean of its divisors is an integer number (29030400).

Almost surely, 2^1561522266 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561522266, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1857945600).

1561522266 is an abundant number, since it is smaller than the sum of its proper divisors (2154368934).

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

1561522266 is a wasteful number, since it uses less digits than its factorization.

1561522266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401 (or 395 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 1561522266 is about 39516.1013512214. The cubic root of 1561522266 is about 1160.1551184754.

The spelling of 1561522266 in words is "one billion, five hundred sixty-one million, five hundred twenty-two thousand, two hundred sixty-six".