100869781 has 2 divisors, whose sum is σ = 100869782. Its totient is φ = 100869780.

The previous prime is 100869761. The next prime is 100869833. The reversal of 100869781 is 187968001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 93219025 + 7650756 = 9655^2 + 2766^2 .

It is a cyclic number.

It is not a de Polignac number, because 100869781 - 2⁹ = 100869269 is a prime.

It is a super-2 number, since 2×100869781² = 20349425437975922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100869731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50434890 + 50434891.

It is an arithmetic number, because the mean of its divisors is an integer number (50434891).

Almost surely, 2^100869781 is an apocalyptic number.

It is an amenable number.

100869781 is a deficient number, since it is larger than the sum of its proper divisors (1).

100869781 is an equidigital number, since it uses as much as digits as its factorization.

100869781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 100869781 is about 10043.3948941581. The cubic root of 100869781 is about 465.5007224202.

The spelling of 100869781 in words is "one hundred million, eight hundred sixty-nine thousand, seven hundred eighty-one".