1526561661 has 16 divisors (see below), whose sum is σ = 2088894080. Its totient is φ = 991293120.

The previous prime is 1526561657. The next prime is 1526561719. The reversal of 1526561661 is 1661656251.

It is not a de Polignac number, because 1526561661 - 2² = 1526561657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1526561261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21646 + ... + 59343.

It is an arithmetic number, because the mean of its divisors is an integer number (130555880).

Almost surely, 2^1526561661 is an apocalyptic number.

It is an amenable number.

1526561661 is a deficient number, since it is larger than the sum of its proper divisors (562332419).

1526561661 is a wasteful number, since it uses less digits than its factorization.

1526561661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81156.

The product of its digits is 64800, while the sum is 39.

The square root of 1526561661 is about 39071.2382834228. The cubic root of 1526561661 is about 1151.4315281852.

The spelling of 1526561661 in words is "one billion, five hundred twenty-six million, five hundred sixty-one thousand, six hundred sixty-one".