3521252561 has 4 divisors (see below), whose sum is σ = 3521378724. Its totient is φ = 3521126400.

The previous prime is 3521252557. The next prime is 3521252599. The reversal of 3521252561 is 1652521253.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1652521253 = 4799 ⋅344347.

It can be written as a sum of positive squares in 2 ways, for example, as 1402951936 + 2118300625 = 37456^2 + 46025^2 .

It is a cyclic number.

It is not a de Polignac number, because 3521252561 - 2² = 3521252557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3521212561) 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, 560 + ... + 83921.

It is an arithmetic number, because the mean of its divisors is an integer number (880344681).

Almost surely, 2^3521252561 is an apocalyptic number.

It is an amenable number.

3521252561 is a deficient number, since it is larger than the sum of its proper divisors (126163).

3521252561 is an equidigital number, since it uses as much as digits as its factorization.

3521252561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126162.

The product of its digits is 18000, while the sum is 32.

The square root of 3521252561 is about 59340.1429135455. The cubic root of 3521252561 is about 1521.3613958591.

The spelling of 3521252561 in words is "three billion, five hundred twenty-one million, two hundred fifty-two thousand, five hundred sixty-one".