17712421 has 2 divisors, whose sum is σ = 17712422. Its totient is φ = 17712420.

The previous prime is 17712413. The next prime is 17712433. The reversal of 17712421 is 12421771.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16112196 + 1600225 = 4014^2 + 1265^2 .

It is a cyclic number.

It is not a de Polignac number, because 17712421 - 2³ = 17712413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17710421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8856210 + 8856211.

It is an arithmetic number, because the mean of its divisors is an integer number (8856211).

Almost surely, 2^17712421 is an apocalyptic number.

It is an amenable number.

17712421 is a deficient number, since it is larger than the sum of its proper divisors (1).

17712421 is an equidigital number, since it uses as much as digits as its factorization.

17712421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 784, while the sum is 25.

The square root of 17712421 is about 4208.6127167987. The cubic root of 17712421 is about 260.6709544264.

The spelling of 17712421 in words is "seventeen million, seven hundred twelve thousand, four hundred twenty-one".