642322021 has 4 divisors (see below), whose sum is σ = 700714944. Its totient is φ = 583929100.

The previous prime is 642321997. The next prime is 642322097. The reversal of 642322021 is 120223246.

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.

It is a cyclic number.

It is not a de Polignac number, because 642322021 - 2⁹ = 642321509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642321983 and 642322001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642322621) 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 3 ways as a sum of consecutive naturals, for example, 29196445 + ... + 29196466.

It is an arithmetic number, because the mean of its divisors is an integer number (175178736).

Almost surely, 2^642322021 is an apocalyptic number.

It is an amenable number.

642322021 is a deficient number, since it is larger than the sum of its proper divisors (58392923).

642322021 is a wasteful number, since it uses less digits than its factorization.

642322021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58392922.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 642322021 is about 25344.0726995485. The cubic root of 642322021 is about 862.8148353113.

Adding to 642322021 its reverse (120223246), we get a palindrome (762545267).

The spelling of 642322021 in words is "six hundred forty-two million, three hundred twenty-two thousand, twenty-one".