42020000021 has 4 divisors (see below), whose sum is σ = 42231156000. Its totient is φ = 41808844044.

The previous prime is 42019999997. The next prime is 42020000041. The reversal of 42020000021 is 12000002024.

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 a de Polignac number, because none of the positive numbers 2^k-42020000021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42019999957 and 42020000011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42020000041) 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, 105577691 + ... + 105578088.

It is an arithmetic number, because the mean of its divisors is an integer number (10557789000).

Almost surely, 2^42020000021 is an apocalyptic number.

It is an amenable number.

42020000021 is a deficient number, since it is larger than the sum of its proper divisors (211155979).

42020000021 is a wasteful number, since it uses less digits than its factorization.

42020000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211155978.

The product of its (nonzero) digits is 32, while the sum is 11.

Adding to 42020000021 its reverse (12000002024), we get a palindrome (54020002045).

The spelling of 42020000021 in words is "forty-two billion, twenty million, twenty-one", and thus it is an aban number and an uban number.