3555220421 has 4 divisors (see below), whose sum is σ = 3764351052. Its totient is φ = 3346089792.

The previous prime is 3555220393. The next prime is 3555220441. The reversal of 3555220421 is 1240225553.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1240225553 = 7 ⋅177175079.

It can be written as a sum of positive squares in 2 ways, for example, as 2397179521 + 1158040900 = 48961^2 + 34030^2 .

It is a cyclic number.

It is not a de Polignac number, because 3555220421 - 2¹⁰ = 3555219397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3555220441) 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, 104565290 + ... + 104565323.

It is an arithmetic number, because the mean of its divisors is an integer number (941087763).

Almost surely, 2^3555220421 is an apocalyptic number.

It is an amenable number.

3555220421 is a deficient number, since it is larger than the sum of its proper divisors (209130631).

3555220421 is a wasteful number, since it uses less digits than its factorization.

3555220421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209130630.

The product of its (nonzero) digits is 12000, while the sum is 29.

The square root of 3555220421 is about 59625.6691450922. The cubic root of 3555220421 is about 1526.2377010687.

Adding to 3555220421 its reverse (1240225553), we get a palindrome (4795445974).

The spelling of 3555220421 in words is "three billion, five hundred fifty-five million, two hundred twenty thousand, four hundred twenty-one".