1611064661 has 4 divisors (see below), whose sum is σ = 1611280524. Its totient is φ = 1610848800.

The previous prime is 1611064643. The next prime is 1611064673. The reversal of 1611064661 is 1664601161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 214622500 + 1396442161 = 14650^2 + 37369^2 .

It is a cyclic number.

It is not a de Polignac number, because 1611064661 - 2⁶ = 1611064597 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 (1611066661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96320 + ... + 111801.

It is an arithmetic number, because the mean of its divisors is an integer number (402820131).

Almost surely, 2^1611064661 is an apocalyptic number.

It is an amenable number.

1611064661 is a deficient number, since it is larger than the sum of its proper divisors (215863).

1611064661 is an equidigital number, since it uses as much as digits as its factorization.

1611064661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215862.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 1611064661 is about 40138.0699710387. The cubic root of 1611064661 is about 1172.2970095776.

The spelling of 1611064661 in words is "one billion, six hundred eleven million, sixty-four thousand, six hundred sixty-one".