1561066766 has 16 divisors (see below), whose sum is σ = 2677678080. Its totient is φ = 668637720.

The previous prime is 1561066729. The next prime is 1561066777. The reversal of 1561066766 is 6676601651.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7070 + ... + 56321.

It is an arithmetic number, because the mean of its divisors is an integer number (167354880).

Almost surely, 2^1561066766 is an apocalyptic number.

1561066766 is a deficient number, since it is larger than the sum of its proper divisors (1116611314).

1561066766 is a wasteful number, since it uses less digits than its factorization.

1561066766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65159.

The product of its (nonzero) digits is 272160, while the sum is 44.

The square root of 1561066766 is about 39510.3374574300. The cubic root of 1561066766 is about 1160.0423007761.

The spelling of 1561066766 in words is "one billion, five hundred sixty-one million, sixty-six thousand, seven hundred sixty-six".