10405721 has 2 divisors, whose sum is σ = 10405722. Its totient is φ = 10405720.

The previous prime is 10405697. The next prime is 10405741. The reversal of 10405721 is 12750401.

It is an a-pointer prime, because the next prime (10405741) can be obtained adding 10405721 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9859600 + 546121 = 3140^2 + 739^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10405721 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 10405693 and 10405702.

It is not a weakly prime, because it can be changed into another prime (10405741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5202860 + 5202861.

It is an arithmetic number, because the mean of its divisors is an integer number (5202861).

Almost surely, 2^10405721 is an apocalyptic number.

It is an amenable number.

10405721 is a deficient number, since it is larger than the sum of its proper divisors (1).

10405721 is an equidigital number, since it uses as much as digits as its factorization.

10405721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 10405721 is about 3225.7899807644. The cubic root of 10405721 is about 218.3185940105.

The spelling of 10405721 in words is "ten million, four hundred five thousand, seven hundred twenty-one".