3261281561 has 4 divisors (see below), whose sum is σ = 3366484224. Its totient is φ = 3156078900.

The previous prime is 3261281539. The next prime is 3261281603. The reversal of 3261281561 is 1651821623.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3261281561 - 2²⁶ = 3194172697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3261281531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52601285 + ... + 52601346.

It is an arithmetic number, because the mean of its divisors is an integer number (841621056).

Almost surely, 2^3261281561 is an apocalyptic number.

3261281561 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

3261281561 is a deficient number, since it is larger than the sum of its proper divisors (105202663).

3261281561 is a wasteful number, since it uses less digits than its factorization.

3261281561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105202662.

The product of its digits is 17280, while the sum is 35.

The square root of 3261281561 is about 57107.6313726983. The cubic root of 3261281561 is about 1482.9599820480.

The spelling of 3261281561 in words is "three billion, two hundred sixty-one million, two hundred eighty-one thousand, five hundred sixty-one".