42001311221 has 4 divisors (see below), whose sum is σ = 42016118892. Its totient is φ = 41986503552.

The previous prime is 42001311199. The next prime is 42001311259. The reversal of 42001311221 is 12211310024.

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 1806675025 + 40194636196 = 42505^2 + 200486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42001311221 is a prime.

It is a super-2 number, since 2×42001311221² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 42001311221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42001311271) 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, 7399580 + ... + 7405253.

It is an arithmetic number, because the mean of its divisors is an integer number (10504029723).

Almost surely, 2^42001311221 is an apocalyptic number.

It is an amenable number.

42001311221 is a deficient number, since it is larger than the sum of its proper divisors (14807671).

42001311221 is a wasteful number, since it uses less digits than its factorization.

42001311221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14807670.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 42001311221 its reverse (12211310024), we get a palindrome (54212621245).

The spelling of 42001311221 in words is "forty-two billion, one million, three hundred eleven thousand, two hundred twenty-one".