100459981 has 2 divisors, whose sum is σ = 100459982. Its totient is φ = 100459980.

The previous prime is 100459979. The next prime is 100459993. The reversal of 100459981 is 189954001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67798756 + 32661225 = 8234^2 + 5715^2 .

It is a cyclic number.

It is not a de Polignac number, because 100459981 - 2¹ = 100459979 is a prime.

It is a super-2 number, since 2×100459981² = 20184415565040722, which contains 22 as substring.

Together with 100459979, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 100459981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100456981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50229990 + 50229991.

It is an arithmetic number, because the mean of its divisors is an integer number (50229991).

Almost surely, 2^100459981 is an apocalyptic number.

It is an amenable number.

100459981 is a deficient number, since it is larger than the sum of its proper divisors (1).

100459981 is an equidigital number, since it uses as much as digits as its factorization.

100459981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 100459981 is about 10022.9726628381. The cubic root of 100459981 is about 464.8694758334.

The spelling of 100459981 in words is "one hundred million, four hundred fifty-nine thousand, nine hundred eighty-one".