3720521 has 8 divisors (see below), whose sum is σ = 4339200. Its totient is φ = 3188724.

The previous prime is 3720511. The next prime is 3720551. The reversal of 3720521 is 1250273.

It is not a de Polignac number, because 3720521 - 2¹⁴ = 3704137 is a prime.

It is a super-2 number, since 2×3720521² = 27684553022882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3720493 and 3720502.

It is not an unprimeable number, because it can be changed into a prime (3720511) 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, 5081 + ... + 5766.

It is an arithmetic number, because the mean of its divisors is an integer number (542400).

Almost surely, 2^3720521 is an apocalyptic number.

It is an amenable number.

3720521 is a deficient number, since it is larger than the sum of its proper divisors (618679).

3720521 is an equidigital number, since it uses as much as digits as its factorization.

3720521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10868 (or 10854 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 3720521 is about 1928.8652104281. The cubic root of 3720521 is about 154.9534511626.

Adding to 3720521 its reverse (1250273), we get a palindrome (4970794).

The spelling of 3720521 in words is "three million, seven hundred twenty thousand, five hundred twenty-one".