3261509661 has 16 divisors (see below), whose sum is σ = 4390145280. Its totient is φ = 2153701440.

The previous prime is 3261509617. The next prime is 3261509677. The reversal of 3261509661 is 1669051623.

It is a de Polignac number, because none of the positive numbers 2^k-3261509661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3261509611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 129055 + ... + 152243.

It is an arithmetic number, because the mean of its divisors is an integer number (274384080).

Almost surely, 2^3261509661 is an apocalyptic number.

It is an amenable number.

3261509661 is a deficient number, since it is larger than the sum of its proper divisors (1128635619).

3261509661 is a wasteful number, since it uses less digits than its factorization.

3261509661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23636.

The product of its (nonzero) digits is 58320, while the sum is 39.

The square root of 3261509661 is about 57109.6284438973. The cubic root of 3261509661 is about 1482.9945548869.

The spelling of 3261509661 in words is "three billion, two hundred sixty-one million, five hundred nine thousand, six hundred sixty-one".