3521405621 has 8 divisors (see below), whose sum is σ = 3589469664. Its totient is φ = 3453675120.

The previous prime is 3521405611. The next prime is 3521405623. The reversal of 3521405621 is 1265041253.

3521405621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 3521405621 - 2¹⁴ = 3521389237 is a prime.

It is a super-2 number, since 2×3521405621² = 24800595095220791282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3521405623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62015 + ... + 104348.

It is an arithmetic number, because the mean of its divisors is an integer number (448683708).

Almost surely, 2^3521405621 is an apocalyptic number.

It is an amenable number.

3521405621 is a deficient number, since it is larger than the sum of its proper divisors (68064043).

3521405621 is a wasteful number, since it uses less digits than its factorization.

3521405621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166771.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 3521405621 is about 59341.4325829770. The cubic root of 3521405621 is about 1521.3834387920.

Adding to 3521405621 its reverse (1265041253), we get a palindrome (4786446874).

The spelling of 3521405621 in words is "three billion, five hundred twenty-one million, four hundred five thousand, six hundred twenty-one".