17972321 has 2 divisors, whose sum is σ = 17972322. Its totient is φ = 17972320.

The previous prime is 17972303. The next prime is 17972329. The reversal of 17972321 is 12327971.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17430625 + 541696 = 4175^2 + 736^2 .

It is a cyclic number.

It is not a de Polignac number, because 17972321 - 2¹⁴ = 17955937 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (17972329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8986160 + 8986161.

It is an arithmetic number, because the mean of its divisors is an integer number (8986161).

Almost surely, 2^17972321 is an apocalyptic number.

It is an amenable number.

17972321 is a deficient number, since it is larger than the sum of its proper divisors (1).

17972321 is an equidigital number, since it uses as much as digits as its factorization.

17972321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5292, while the sum is 32.

The square root of 17972321 is about 4239.3774307084. The cubic root of 17972321 is about 261.9397380973.

The spelling of 17972321 in words is "seventeen million, nine hundred seventy-two thousand, three hundred twenty-one".