100030781 has 2 divisors, whose sum is σ = 100030782. Its totient is φ = 100030780.

The previous prime is 100030753. The next prime is 100030807. The reversal of 100030781 is 187030001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 82973881 + 17056900 = 9109^2 + 4130^2 .

It is a cyclic number.

It is not a de Polignac number, because 100030781 - 2¹⁸ = 99768637 is a prime.

It is a super-2 number, since 2×100030781² = 20012314294939922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100030741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50015390 + 50015391.

It is an arithmetic number, because the mean of its divisors is an integer number (50015391).

Almost surely, 2^100030781 is an apocalyptic number.

It is an amenable number.

100030781 is a deficient number, since it is larger than the sum of its proper divisors (1).

100030781 is an equidigital number, since it uses as much as digits as its factorization.

100030781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 100030781 is about 10001.5389315845. The cubic root of 100030781 is about 464.2065027243.

Adding to 100030781 its reverse (187030001), we get a palindrome (287060782).

The spelling of 100030781 in words is "one hundred million, thirty thousand, seven hundred eighty-one".