642021663 has 8 divisors (see below), whose sum is σ = 863882800. Its totient is φ = 424087488.

The previous prime is 642021631. The next prime is 642021673. The reversal of 642021663 is 366120246.

642021663 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 642021663 - 2⁵ = 642021631 is a prime.

It is a super-2 number, since 2×642021663² = 824383631522571138, which contains 22 as substring.

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 642021663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642021613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 981358 + ... + 982011.

It is an arithmetic number, because the mean of its divisors is an integer number (107985350).

Almost surely, 2^642021663 is an apocalyptic number.

642021663 is a deficient number, since it is larger than the sum of its proper divisors (221861137).

642021663 is a wasteful number, since it uses less digits than its factorization.

642021663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1963481.

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 642021663 is about 25338.1464002401. The cubic root of 642021663 is about 862.6803265889.

The spelling of 642021663 in words is "six hundred forty-two million, twenty-one thousand, six hundred sixty-three".