100442561 has 4 divisors (see below), whose sum is σ = 100642752. Its totient is φ = 100242372.

The previous prime is 100442557. The next prime is 100442567. The reversal of 100442561 is 165244001.

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 not a de Polignac number, because 100442561 - 2² = 100442557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100442567) 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, 99341 + ... + 100346.

It is an arithmetic number, because the mean of its divisors is an integer number (25160688).

Almost surely, 2^100442561 is an apocalyptic number.

It is an amenable number.

100442561 is a deficient number, since it is larger than the sum of its proper divisors (200191).

100442561 is an equidigital number, since it uses as much as digits as its factorization.

100442561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200190.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 100442561 is about 10022.1036214958. The cubic root of 100442561 is about 464.8426044553.

Adding to 100442561 its reverse (165244001), we get a palindrome (265686562).

The spelling of 100442561 in words is "one hundred million, four hundred forty-two thousand, five hundred sixty-one".