3900521 has 4 divisors (see below), whose sum is σ = 3909444. Its totient is φ = 3891600.

The previous prime is 3900517. The next prime is 3900563. The reversal of 3900521 is 1250093.

3900521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2310400 + 1590121 = 1520^2 + 1261^2 .

It is a cyclic number.

It is not a de Polignac number, because 3900521 - 2² = 3900517 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 3900493 and 3900502.

It is not an unprimeable number, because it can be changed into a prime (3900581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3770 + ... + 4691.

It is an arithmetic number, because the mean of its divisors is an integer number (977361).

Almost surely, 2^3900521 is an apocalyptic number.

It is an amenable number.

3900521 is a deficient number, since it is larger than the sum of its proper divisors (8923).

3900521 is an equidigital number, since it uses as much as digits as its factorization.

3900521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8922.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 3900521 is about 1974.9736707106. The cubic root of 3900521 is about 157.4131006309.

The spelling of 3900521 in words is "three million, nine hundred thousand, five hundred twenty-one".