3556621 has 4 divisors (see below), whose sum is σ = 3765852. Its totient is φ = 3347392.

The previous prime is 3556607. The next prime is 3556649. The reversal of 3556621 is 1266553.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1266553 = 59 ⋅21467.

It can be written as a sum of positive squares in 2 ways, for example, as 1188100 + 2368521 = 1090^2 + 1539^2 .

It is a cyclic number.

It is not a de Polignac number, because 3556621 - 2⁷ = 3556493 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3556621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3556601) 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, 104590 + ... + 104623.

It is an arithmetic number, because the mean of its divisors is an integer number (941463).

Almost surely, 2^3556621 is an apocalyptic number.

It is an amenable number.

3556621 is a deficient number, since it is larger than the sum of its proper divisors (209231).

3556621 is a wasteful number, since it uses less digits than its factorization.

3556621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209230.

The product of its digits is 5400, while the sum is 28.

The square root of 3556621 is about 1885.9005806245. The cubic root of 3556621 is about 152.6438095191.

The spelling of 3556621 in words is "three million, five hundred fifty-six thousand, six hundred twenty-one".