42120000221 has 4 divisors (see below), whose sum is σ = 45360000252. Its totient is φ = 38880000192.

The previous prime is 42120000191. The next prime is 42120000233. The reversal of 42120000221 is 12200002124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6874068100 + 35245932121 = 82910^2 + 187739^2 .

It is a cyclic number.

It is not a de Polignac number, because 42120000221 - 2²² = 42115805917 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 42120000196 and 42120000205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42120003221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1619999996 + ... + 1620000021.

It is an arithmetic number, because the mean of its divisors is an integer number (11340000063).

Almost surely, 2^42120000221 is an apocalyptic number.

It is an amenable number.

42120000221 is a deficient number, since it is larger than the sum of its proper divisors (3240000031).

42120000221 is a wasteful number, since it uses less digits than its factorization.

42120000221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3240000030.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 42120000221 its reverse (12200002124), we get a palindrome (54320002345).

The spelling of 42120000221 in words is "forty-two billion, one hundred twenty million, two hundred twenty-one", and thus it is an aban number.