3591021 has 16 divisors (see below), whose sum is σ = 5500928. Its totient is φ = 2041200.

The previous prime is 3591017. The next prime is 3591023. The reversal of 3591021 is 1201953.

It is not a de Polignac number, because 3591021 - 2² = 3591017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

3591021 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3591023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5376 + ... + 6006.

It is an arithmetic number, because the mean of its divisors is an integer number (343808).

Almost surely, 2^3591021 is an apocalyptic number.

It is an amenable number.

3591021 is a deficient number, since it is larger than the sum of its proper divisors (1909907).

3591021 is a wasteful number, since it uses less digits than its factorization.

3591021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 912.

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 3591021 is about 1894.9989445907. The cubic root of 3591021 is about 153.1343601664.

Adding to 3591021 its reverse (1201953), we get a palindrome (4792974).

The spelling of 3591021 in words is "three million, five hundred ninety-one thousand, twenty-one".