1641503561 has 8 divisors (see below), whose sum is σ = 1739783304. Its totient is φ = 1543415040.

The previous prime is 1641503531. The next prime is 1641503581. The reversal of 1641503561 is 1653051461.

It can be written as a sum of positive squares in 4 ways, for example, as 1032401161 + 609102400 = 32131^2 + 24680^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1641503561 - 2⁶ = 1641503497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1641503531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29930 + ... + 64643.

It is an arithmetic number, because the mean of its divisors is an integer number (217472913).

Almost surely, 2^1641503561 is an apocalyptic number.

It is an amenable number.

1641503561 is a deficient number, since it is larger than the sum of its proper divisors (98279743).

1641503561 is a wasteful number, since it uses less digits than its factorization.

1641503561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95611.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 1641503561 is about 40515.4731059629. The cubic root of 1641503561 is about 1179.6339861172.

The spelling of 1641503561 in words is "one billion, six hundred forty-one million, five hundred three thousand, five hundred sixty-one".