1721407901 has 2 divisors, whose sum is σ = 1721407902. Its totient is φ = 1721407900.

The previous prime is 1721407889. The next prime is 1721407931. The reversal of 1721407901 is 1097041271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 958212025 + 763195876 = 30955^2 + 27626^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1721407901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1721407931) 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, 860703950 + 860703951.

It is an arithmetic number, because the mean of its divisors is an integer number (860703951).

Almost surely, 2^1721407901 is an apocalyptic number.

It is an amenable number.

1721407901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1721407901 is an equidigital number, since it uses as much as digits as its factorization.

1721407901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 32.

The square root of 1721407901 is about 41489.8529884115. The cubic root of 1721407901 is about 1198.4721066012.

The spelling of 1721407901 in words is "one billion, seven hundred twenty-one million, four hundred seven thousand, nine hundred one".