1608420421 has 4 divisors (see below), whose sum is σ = 1614536352. Its totient is φ = 1602304492.

The previous prime is 1608420419. The next prime is 1608420491. The reversal of 1608420421 is 1240248061.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1240248061 = 13 ⋅95403697.

It is a cyclic number.

It is not a de Polignac number, because 1608420421 - 2¹ = 1608420419 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 1608420421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1608420491) 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, 3057571 + ... + 3058096.

It is an arithmetic number, because the mean of its divisors is an integer number (403634088).

Almost surely, 2^1608420421 is an apocalyptic number.

It is an amenable number.

1608420421 is a deficient number, since it is larger than the sum of its proper divisors (6115931).

1608420421 is an equidigital number, since it uses as much as digits as its factorization.

1608420421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6115930.

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 1608420421 is about 40105.1171423299. The cubic root of 1608420421 is about 1171.6552947772.

Adding to 1608420421 its reverse (1240248061), we get a palindrome (2848668482).

The spelling of 1608420421 in words is "one billion, six hundred eight million, four hundred twenty thousand, four hundred twenty-one".