642425421 has 24 divisors (see below), whose sum is σ = 942938080. Its totient is φ = 388761120.

The previous prime is 642425401. The next prime is 642425449. The reversal of 642425421 is 124524246.

It is not a de Polignac number, because 642425421 - 2¹³ = 642417229 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 (642425401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 439590 + ... + 441048.

Almost surely, 2^642425421 is an apocalyptic number.

It is an amenable number.

642425421 is a deficient number, since it is larger than the sum of its proper divisors (300512659).

642425421 is a wasteful number, since it uses less digits than its factorization.

642425421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2697 (or 2686 counting only the distinct ones).

The product of its digits is 15360, while the sum is 30.

The square root of 642425421 is about 25346.1125421631. The cubic root of 642425421 is about 862.8611310240.

Adding to 642425421 its reverse (124524246), we get a palindrome (766949667).

The spelling of 642425421 in words is "six hundred forty-two million, four hundred twenty-five thousand, four hundred twenty-one".