1544531661 has 6 divisors (see below), whose sum is σ = 2230990190. Its totient is φ = 1029687768.

The previous prime is 1544531633. The next prime is 1544531669. The reversal of 1544531661 is 1661354451.

1544531661 is a `hidden beast` number, since 1 + 544 + 53 + 1 + 6 + 61 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1164515625 + 380016036 = 34125^2 + 19494^2 .

It is not a de Polignac number, because 1544531661 - 2⁵ = 1544531629 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 (1544531669) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 85807306 + ... + 85807323.

Almost surely, 2^1544531661 is an apocalyptic number.

It is an amenable number.

1544531661 is a deficient number, since it is larger than the sum of its proper divisors (686458529).

1544531661 is a wasteful number, since it uses less digits than its factorization.

1544531661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171614635 (or 171614632 counting only the distinct ones).

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

The square root of 1544531661 is about 39300.5300345937. The cubic root of 1544531661 is about 1155.9319604614.

The spelling of 1544531661 in words is "one billion, five hundred forty-four million, five hundred thirty-one thousand, six hundred sixty-one".