642226161601 has 4 divisors (see below), whose sum is σ = 643709363332. Its totient is φ = 640742959872.

The previous prime is 642226161559. The next prime is 642226161607. The reversal of 642226161601 is 106161622246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 106161622246 = 2 ⋅53080811123.

It can be written as a sum of positive squares in 2 ways, for example, as 64589681025 + 577636480576 = 254145^2 + 760024^2 .

It is a cyclic number.

It is not a de Polignac number, because 642226161601 - 2¹³ = 642226153409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642226161607) 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, 741600216 + ... + 741601081.

It is an arithmetic number, because the mean of its divisors is an integer number (160927340833).

Almost surely, 2^642226161601 is an apocalyptic number.

It is an amenable number.

642226161601 is a deficient number, since it is larger than the sum of its proper divisors (1483201731).

642226161601 is a wasteful number, since it uses less digits than its factorization.

642226161601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1483201730.

The product of its (nonzero) digits is 41472, while the sum is 37.

Adding to 642226161601 its reverse (106161622246), we get a palindrome (748387783847).

The spelling of 642226161601 in words is "six hundred forty-two billion, two hundred twenty-six million, one hundred sixty-one thousand, six hundred one".