103809721 has 2 divisors, whose sum is σ = 103809722. Its totient is φ = 103809720.

The previous prime is 103809709. The next prime is 103809751. The reversal of 103809721 is 127908301.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102738496 + 1071225 = 10136^2 + 1035^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-103809721 is a prime.

It is not a weakly prime, because it can be changed into another prime (103809751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51904860 + 51904861.

It is an arithmetic number, because the mean of its divisors is an integer number (51904861).

Almost surely, 2^103809721 is an apocalyptic number.

It is an amenable number.

103809721 is a deficient number, since it is larger than the sum of its proper divisors (1).

103809721 is an equidigital number, since it uses as much as digits as its factorization.

103809721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 103809721 is about 10188.7055605705. The cubic root of 103809721 is about 469.9799614212.

The spelling of 103809721 in words is "one hundred three million, eight hundred nine thousand, seven hundred twenty-one".